The calculation before your next step
Calculators & Converters
Check a date, dataset, measurement, project quantity, electrical relationship, technical unit conversion, fraction, geometry problem, screen density, media bitrate or file-planning value. MAXScanner keeps units, formulas, editable assumptions and working visible so you can verify the number instead of trusting a black box.
Interactive inputs appear before the long-form explanation.
The math, units and assumptions remain visible beside the answer.
Construction, electrical, conversions, statistics, fractions, geometry and media have dedicated collections.
Supplier, manufacturer, drawing and standards data remain authoritative where required.
Browse calculator collections
Start with the job you are doing rather than scrolling one flat list. Each collection groups genuinely different calculations around a coherent workflow.
Measurement Calculators
Work with tape-measure dimensions, drawing scales, area and unit conversions.
Explore collectionConstruction & DIY Calculators
Estimate area, concrete and tile quantities with visible assumptions and formulas.
Explore collectionElectrical & Engineering Calculators
Solve foundational voltage, current, resistance and power relationships without hiding the formulas.
Explore collectionStatistics Calculators
Paste datasets or enter study assumptions to calculate descriptive statistics, spread, correlation, regression, sample size, margin of error and exact combinatorics with formulas and working kept visible.
Explore collectionFraction Calculators
Work with fractions, decimals, mixed numbers and practical inch fractions with the simplifying steps kept visible.
Explore collectionGeometry Calculators
Solve common 2D area, right triangles, general triangles, circles, rectangles, perimeter, volume and slope from explicit dimensions and formulas.
Explore collectionScreen, Image & Video Calculators
Plan pixel density, physical screen dimensions, aspect ratios, video bitrate and file size before resizing, converting or compressing media.
Explore collectionMoney & Business Calculators
Model debt payoff, debt-to-income ratios, investment fee drag, discounted cash flows, IRR and sales commission with assumptions and working exposed.
Explore collectionEveryday Planning Calculators
Solve practical planning, weather, science, logistics and engineering jobs with editable assumptions and visible working.
Explore collectionHigh-intent project, conversion & statistics tools
Newest deep calculators
These tools combine editable assumptions, multiple useful outputs, worked math and strong next-step links instead of stopping at one naked number.
construction diy
Brick Calculator — Bricks, Mortar, Cement, Sand & Cost
Estimate bricks for one or more walls after opening deductions, then calculate wet and dry mortar, cement bags, sand volume and optional material cost from actual brick dimensions and mortar-joint inputs.
construction diy
Concrete Block Calculator — CMU Blocks, Mortar, Grout, Pallets & Cost
Estimate concrete blocks for a wall after opening deductions, then plan mortar bags, pallets and optional core-fill grout from actual block-face dimensions and editable product coverage, void fraction and bag-yield inputs.
construction diy
Asphalt Calculator — Compacted Volume, Tons, Truckloads & Cost
Calculate compacted asphalt volume, base mass, order tonnage, optional loose-volume planning, truckloads and material cost from measured area, finished thickness, entered density and order allowance in imperial or metric units.
construction diy
Tank Volume Calculator — Capacity, Partial Fill, Gallons, Litres & Weight
Calculate total and partial-fill volume for rectangular, vertical-cylinder, horizontal-cylinder, horizontal-elliptical, horizontal-capsule and spherical tanks, with litres, US/Imperial gallons, remaining capacity, liquid weight and optional fill/drain time.
construction diy
Pipe Volume Calculator — Litres, Gallons, Partial Fill, Weight & Fill Time
Calculate pipe internal capacity from actual bore or outside diameter plus wall thickness, including partial horizontal fill, multiple runs, fittings-length allowance, litres/gallons, fluid weight, volume per metre and optional fill/drain time.
measurements
Pressure Converter — PSI, Bar, kPa, MPa, atm, Torr & mmHg
Convert pressure instantly between Pa, hPa, kPa, MPa, GPa, bar, mbar, psi, ksi, atm, Torr, mmHg, inHg and kgf/cm², with every equivalent, the direct factor, adjustable precision and gauge-vs-absolute guidance.
measurements
Torque Unit Converter — N·m, lb·ft, lb·in, oz·in & kgf·m
Convert torque between N·m, kN·m, mN·m, lbf·ft, lbf·in, ozf·in, kgf·m, kgf·cm and gf·cm with every equivalent, adjustable precision and a direct conversion factor.
measurements
Energy Unit Converter — J, kJ, MJ, kWh, Calories, BTU & eV
Convert energy between joules, kJ, MJ, GJ, Wh, kWh, MWh, calories, food Calories, BTU, electronvolts, ft·lbf and ergs, with all equivalents, scientific notation and clear energy-vs-power context.
statistics
Statistics Calculator — Mean, Median, Mode, Quartiles, Variance & Standard Deviation
Paste a dataset and calculate count, sum, mean, median, modes, min/max/range, Tukey quartiles, IQR, sample/population variance and standard deviation, standard error, coefficient of variation, skewness, excess kurtosis, outlier fences and a frequency table.
statistics
Standard Deviation Calculator — Sample & Population Variance with Steps
Calculate sample or population standard deviation from pasted data with mean, variance, squared-deviation sum, standard error, coefficient of variation, Tukey outliers and a row-by-row deviation and z-score table.
statistics
Weighted Average Calculator — Values, Weights, Contributions & Plain Average
Paste value-and-weight rows to calculate the weighted mean, weighted sum, total weight, plain average, weighting shift and each row’s normalized weight percentage, product and contribution, without requiring weights to total 100.
Search-driven date engine
Dates from today — direct answers plus a real calculator
Find a common date instantly, then change the amount, unit, direction or starting date without opening a different tool. Exact pages include weekday, ISO week, day-of-year and weekday-vs-calendar context.
Open Days From Today Calculator →What Date Is 7 days From Today?
Find the exact calendar date 7 days from today, with weekday, ISO week, day-of-year, calendar/weekday breakdown and a reusable date calculator.
What Date Is 30 days From Today?
Find the exact calendar date 30 days from today, with weekday, ISO week, day-of-year, calendar/weekday breakdown and a reusable date calculator.
What Date Is 60 days From Today?
Find the exact calendar date 60 days from today, with weekday, ISO week, day-of-year, calendar/weekday breakdown and a reusable date calculator.
What Date Is 90 days From Today?
Find the exact calendar date 90 days from today, with weekday, ISO week, day-of-year, calendar/weekday breakdown and a reusable date calculator.
What Date Was 60 days Ago?
Find the exact calendar date 60 days ago, with weekday, ISO week, day-of-year, calendar/weekday breakdown and a reusable date calculator.
Project and engineering foundation
These measurement, construction and electrical tools anchor many of the deeper project journeys.
Feet and Inches Calculator
Add, subtract, multiply, divide or convert feet and inches, including decimal and fractional inch inputs, with decimal feet and metric equivalents.
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Square Footage Calculator
Calculate square footage for rectangles, circles and triangles, convert the area to square meters and estimate cost from a price per square foot.
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Scale Calculator — Drawings, Maps and Models
Convert real measurements to scaled drawing or model sizes, convert scaled sizes back to real dimensions, or find the 1:N scale ratio.
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Ohm's Law Calculator — Volts, Amps, Ohms and Watts
Calculate voltage, current, resistance and power from any two positive electrical values using Ohm's Law and Watt's Law.
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Watts to Amps Calculator — DC, Single-Phase and Three-Phase
Convert watts to amps from power and voltage for DC, single-phase AC or balanced three-phase AC, with an explicit power-factor input for AC loads.
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Concrete Calculator — Slab and Cylinder Volume
Estimate concrete volume for a rectangular slab or cylindrical pour in cubic feet, cubic yards and cubic meters, with an optional waste allowance.
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Tile Calculator — Tiles, Boxes and Waste Allowance
Estimate tiles needed from room dimensions and tile size, add a waste allowance, then optionally calculate boxes and simple material cost.
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Material & power calculators
Board footage, flooring, roofing, gravel and power calculations keep package coverage, density, tariff, phase and PF assumptions visible.
Advanced project & electrical tools
Paint, pavers, stairs, diagonal checks, kVA/current and three-phase power keep their assumptions explicit.
More date questions, one intent per tool
Weekday, week-span, age-gap, year-span and leap-year queries have different outputs, so they are separate calculators rather than keyword aliases of one page.
Day of Week Calculator — Weekday, ISO Week & Day of Year
Enter any valid calendar date to find its weekday, ISO week number, day of year and leap-year context without relying on a locale-specific date parser.
Weeks Between Dates Calculator — Weeks, Days & Decimal Weeks
Calculate the elapsed calendar days between two dates as full weeks plus remaining days and decimal weeks, without silently adding an inclusive endpoint.
Age Difference Calculator — Years, Months, Days & Total Days
Compare two birth dates or milestone dates and calculate the exact calendar gap in years, months and days plus total days and weeks.
Years Between Dates Calculator — Exact Gap & Decimal Years
Calculate exact completed years, months and days between two dates, plus total days, weeks and an average-length decimal-year estimate.
Leap Year Calculator — Check Any Gregorian Year
Check whether a year is a Gregorian leap year, see why the divisible-by-100 exception matters, and find the previous and next leap years.
Unit conversion references
Need factors and common values, not just one conversion? Use source-unit references for length, volume, weight and speed, then open the technical converters for pressure, torque, force, energy, power, angle and data rate.
Browse unit conversion tables →Popular exact conversions
Need a high-demand technical pair immediately? Open a direct-answer page to see the factor, formula and the full converter for another value.
PSI to Bar Converter
0.0689476 bar
See formula and convert another value →
Bar to PSI Converter
14.5037738 psi
See formula and convert another value →
N·m to ft·lb Torque Converter
0.737562149 lbf·ft
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kW to Horsepower Converter
1.34102209 hp
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Degrees to Radians Converter
0.0174532925 rad
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Mbps to MB/s Converter
0.125 MB/s
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How MAXScanner treats calculator content
We publish the formula, inputs, assumptions, limits and worked example on the same page as the calculator. We do not invent expert reviewers, star ratings or “standard” product values to make a page look authoritative. Where a supplier, manufacturer, drawing or applicable standard owns the answer, the calculator says so.
Find your calculator
Search titles, tasks, formulas and units across the calculator library.
564 calculators
File planning
Printing Cost Calculator
Estimate print-job cost from ink, toner, paper and labor. Count PDF pages locally, compare duplex sheets and save scenarios with a downloadable cost report.
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Everyday math
Number Base Converter — Binary, Decimal, Hex & Octal
Convert exact integers between binary, decimal, hexadecimal and octal. Check signed bit widths and export batch results with row-level errors.
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Time & dates
Days Between Dates Calculator
Calculate the exact number of days between two dates.
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Time & dates
Age Calculator
Calculate exact age in years, months and days.
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Time & dates
Add Days to Date Calculator
Add days, weeks or months to any date.
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Time & dates
Subtract Days from Date Calculator
Subtract days, weeks or months from any date.
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Time & dates
Business Days Calculator
Count working days between dates excluding weekends and supplied holidays.
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Time & dates
Time Duration Calculator
Calculate elapsed time between two times including overnight durations.
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Time & dates
Hours Between Times Calculator
Calculate hours and minutes between two times, including overnight and decimal hours.
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Work & productivity
Hours Worked Calculator
Calculate hours worked, breaks, net hours and decimal hours.
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Work & productivity
Time Card Calculator
Calculate weekly work hours, breaks, overtime and optional estimated pay.
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Work & productivity
Shift Hours Calculator
Calculate net shift hours, breaks, overnight work and optional pay.
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Time & dates
Time Difference Calculator
Calculate elapsed time between two dates and times.
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Time & dates
Decimal Hours Calculator
Convert hours, minutes and seconds to decimal hours and back.
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Time & dates
Hours to Minutes Converter
Convert hours or decimal hours into total minutes.
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Time & dates
Minutes to Hours Converter
Convert total minutes into hours, minutes, seconds and decimal hours.
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Time & dates
Add Time Calculator
Add hours, minutes and seconds to a clock time with day rollover support.
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Time & dates
Subtract Time Calculator
Subtract hours, minutes and seconds from a clock time with day rollover support.
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Work & productivity
Overtime Calculator
Estimate an overtime hourly rate and overtime pay from base pay, working schedule, overtime hours and a multiplier.
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Time & dates
Hourly to Salary Calculator
Convert hourly pay to annual salary or annual salary to an hourly rate using configurable hours per week and paid weeks per year, with daily, weekly, biweekly and monthly equivalents.
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Work & productivity
Business Hours Calculator
Calculate Monday-to-Friday working time between dates from workday hours and breaks.
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Work & productivity
Work Hours Per Week Calculator
Calculate weekly, average monthly and yearly work hours from daily hours and work days per week.
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Work & productivity
Weekly Hours Calculator
Add enabled daily shifts across a week with breaks, decimal hours and an overtime threshold.
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Work & productivity
Payroll Hours Calculator
Convert enabled weekly shifts into regular hours, overtime hours and optional estimated pay.
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Time & dates
Meeting Duration Calculator
Calculate meeting duration and total meeting hours from start and end times.
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Time & dates
Time Until Calculator
Find the live time remaining until a future date and time.
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Time & dates
Time Since Calculator
Find the live time elapsed since a past date and time.
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Time & dates
Date and Time Calculator
Add or subtract a duration from a base date and time and inspect the resulting timestamp.
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Time & dates
Sleep Duration Calculator: How Long Did I Sleep?
Calculate sleep duration between bedtime and wake-up time, including overnight sleep.
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Time & dates
Flight Duration Calculator
Estimate elapsed flight time from departure and arrival date-times entered in the same time-zone basis.
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Time & dates
Elapsed Time Calculator
Calculate elapsed time between two clock times with overnight rollover and total minutes and seconds.
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Time & dates
Time Zone Converter
Convert a date and time between IANA time zones with DST-aware offsets and date changes.
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Time & dates
Time Zone Duration Calculator
Compare two time zones at a selected date and time, including UTC offset difference and calendar-day changes.
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Time & dates
Meeting Time Zone Calculator
Compare working-hour overlap across two time zones with DST-aware conversion.
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Time & dates
DST-Aware Time Calculator
Convert times using the browser IANA time-zone database so daylight-saving changes apply for the selected date.
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Time & dates
World Clock Difference Calculator
Compare local times, UTC offsets and date changes across selected world time zones.
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Time & dates
Business Time Across Time Zones Calculator
Compare selected working-hour windows across time zones and total their overlap over the next 24 hours.
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Time & dates
Mumbai to New York Time Converter
Convert Mumbai India time to New York time with date changes and daylight-saving adjustments.
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Time & dates
India to London Time Converter
Convert India Standard Time to London time with daylight-saving-aware results.
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Time & dates
New York to London Time Converter
Convert New York time to London time with daylight-saving-aware date and offset handling.
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Time & dates
Los Angeles to Tokyo Time Converter
Convert Los Angeles time to Tokyo time with DST-aware date changes.
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Time & dates
Dubai to India Time Converter
Convert Dubai time to India Standard Time and show the local date and offset.
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Time & dates
UTC to India Time Converter
Convert UTC to India Standard Time with a clear local date and time.
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Time & dates
EST to IST Converter (US Eastern to India Time)
Convert EST/EDT (New York) to India Standard Time with the right DST offset for the date. IST is 10:30 ahead of EST and 9:30 ahead of EDT.
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Time & dates
PST to IST Converter (US Pacific to India Time)
Convert PST/PDT (Los Angeles) to India Standard Time with the right DST offset for the date. IST is 13:30 ahead of PST and 12:30 ahead of PDT.
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Money & business
Discount Calculator
Calculate discount amount and final price from an original price and discount percentage.
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Money & business
Sales Tax Calculator
Calculate tax amount and final price from a price and tax percentage.
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Everyday math
Percentage Increase Calculator
Calculate percentage increase or decrease between two values, with an explicit undefined result when the starting value is zero.
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Everyday math
Ratio Calculator
Simplify integer or decimal ratios, solve a missing proportion value, scale a ratio, and split a total into proportional shares with visible working.
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Everyday math
Average Calculator
Calculate the arithmetic mean of the non-empty values entered.
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Money & business
Simple Interest Calculator
Calculate simple interest and total amount from principal, annual rate and time.
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Money & business
Compound Interest Calculator
Calculate compound growth, total interest and future value with configurable compounding frequency.
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Money & business
Savings Calculator
Estimate future savings from regular end-of-month contributions and an annual rate.
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Measurements
Speed Converter
Convert nonnegative speed between meters per second, kilometers per hour, miles per hour, knots and feet per second.
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Measurements
Temperature Converter
Convert temperatures between Celsius, Fahrenheit and Kelvin and reject values below absolute zero.
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Measurements
Area Converter
Convert square meters, square feet, square yards, acres and hectares.
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Measurements
Volume Converter
Convert liters, milliliters, cubic meters, US liquid gallons and cubic feet.
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Measurements
Length Converter
Convert meters, centimeters, millimeters, kilometers, inches, feet, yards and miles with exact standard factors.
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Measurements
Weight Converter
Convert kilograms, grams, pounds and ounces using standard mass conversion factors.
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Money & business
SIP Calculator
Estimate SIP future value from monthly investment, expected annual return and investment period using a stated monthly contribution timing assumption.
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Money & business
GST Calculator
Calculate GST amount and base/final price for tax-added or tax-inclusive inputs.
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Money & business
FD Calculator
Estimate fixed-deposit maturity and interest from principal, annual rate, tenure and compounding frequency.
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Money & business
CAGR Calculator
Calculate compound annual growth rate from positive starting value, ending value and investment period.
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Money & business
Profit Margin Calculator
Calculate profit, markup and profit margin from nonnegative cost and positive selling price.
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Money & business
Break Even Calculator
Calculate break-even units and revenue when selling price exceeds variable cost.
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Work & productivity
Study Time Calculator: Sessions, Breaks & Hours
Plan focused study sessions inside an available time window, including breaks and unused time.
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Work & productivity
Deadline Calculator
Calculate daily target hours across the scheduled study days remaining before a deadline.
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Work & productivity
Pomodoro Time Calculator
Calculate Pomodoro sessions, focused work, short breaks, long breaks and total elapsed planning time.
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Work & productivity
Focus Time Calculator
Calculate how much focused work fits between two times after accounting for breaks.
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Work & productivity
Project Duration Calculator
Estimate project workdays and finish date from total work hours, daily capacity and one to seven scheduled work days per week.
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Work & productivity
Workday End Time Calculator
Calculate the local date and time when a workday ends from start time, work hours and break time.
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Time & dates
Week Number Calculator
Find the ISO 8601 week number and Monday-to-Sunday date range.
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Time & dates
Countdown Timer
Create a live countdown to any date and time.
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Time & dates
Christmas 2026 Countdown
Live countdown to Christmas Day 2026 in the viewer’s local time.
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Time & dates
New Year 2027 Countdown
Live countdown to January 1, 2027 in the viewer’s local time.
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File planning
File Size Converter
Convert bytes, decimal KB/MB/GB/TB and binary KiB/MiB/GiB/TiB. Check individual files or their total against inclusive or strict upload limits.
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File planning
Data Transfer Time Calculator
Estimate upload, download or backup time from file size and speed. Compare actual original and output bytes, usable throughput and hypothetical compression savings.
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Time & dates
Data Usage Calculator
Estimate daily, billing-cycle and yearly data use from hours per day, a measured or assumed MB-per-hour rate and active days per month.
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Time & dates
Bandwidth Calculator
Size a shared link from concurrent users, peak Mbps per active user and headroom. Compare base demand, planned Mbps, MB/s, 1 Gbps utilization and sustained transfer context.
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Time & dates
Backup Time Calculator
Estimate backup duration from data size, sustained line speed and usable-throughput efficiency, with ideal-time and efficiency-penalty comparisons.
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Time & dates
Download Time Calculator
Estimate download time from file size, connection speed and usable-throughput efficiency.
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Time & dates
Upload Time Calculator
Estimate upload time from file size, upload speed and usable-throughput efficiency.
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Measurements
Feet and Inches Calculator
Add, subtract, multiply, divide or convert feet and inches, including decimal and fractional inch inputs, with decimal feet and metric equivalents.
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General material planning
Square Footage Calculator
Calculate square footage for rectangles, circles and triangles, convert the area to square meters and estimate cost from a price per square foot.
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Measurements
Scale Calculator — Drawings, Maps and Models
Convert real measurements to scaled drawing or model sizes, convert scaled sizes back to real dimensions, or find the 1:N scale ratio.
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Electrical & engineering
Ohm's Law Calculator — Volts, Amps, Ohms and Watts
Calculate voltage, current, resistance and power from any two positive electrical values using Ohm's Law and Watt's Law.
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Electrical & engineering
Watts to Amps Calculator — DC, Single-Phase and Three-Phase
Convert watts to amps from power and voltage for DC, single-phase AC or balanced three-phase AC, with an explicit power-factor input for AC loads.
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Concrete & masonry
Concrete Calculator — Slab and Cylinder Volume
Estimate concrete volume for a rectangular slab or cylindrical pour in cubic feet, cubic yards and cubic meters, with an optional waste allowance.
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General material planning
Tile Calculator — Tiles, Boxes and Waste Allowance
Estimate tiles needed from room dimensions and tile size, add a waste allowance, then optionally calculate boxes and simple material cost.
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Carpentry & interiors
Board Foot Calculator — Lumber Volume & Cost Basis
Calculate board feet from lumber thickness, width, length and quantity, then add an optional waste allowance for a project tally.
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Carpentry & interiors
Flooring Calculator — Square Feet, Waste & Boxes
Add up to three room areas, apply a user-selected waste allowance and estimate whole boxes from the exact coverage printed on the flooring package.
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Roofing & exterior
Roof Pitch Calculator — Rise, Run, Angle & Slope
Convert roof rise and run into pitch per 12, angle in degrees, percent slope and slope factor, with an optional rafter-line geometry result.
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Decks, fences & landscape
Gravel Calculator — Cubic Yards & Tons
Estimate gravel volume from length, width and depth, add a project allowance and convert cubic yards to tons using a density you can verify with the supplier.
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Electrical & engineering
Amps to Watts Calculator — DC, Single-Phase & Three-Phase
Convert current in amps to real power in watts for DC, single-phase AC or balanced three-phase AC with explicit voltage and power-factor inputs.
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Electrical & engineering
kW to Amps Calculator — DC, Single-Phase & Three-Phase
Convert kilowatts to amps from voltage, system type and power factor for DC, single-phase AC or balanced three-phase AC.
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Electrical & engineering
Electricity Cost Calculator — kWh & Energy Cost
Estimate energy use in kWh and simple electricity cost from device watts, hours per day, number of days and your own tariff per kWh.
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Electrical & engineering
Power Factor Calculator — kW, kVA & kVAR
Calculate power factor from real power and apparent power, or derive kVA and reactive power from kW and a known power factor.
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General material planning
Paint Calculator — Walls, Ceiling, Coats & Containers
Estimate paint volume from room dimensions, exact opening area, separate wall and ceiling coats, product coverage, waste and optional container size and price.
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Decks, fences & landscape
Paver Calculator — Pavers, Waste, Base & Bedding Volume
Estimate paver count from project and paver dimensions, apply a user-selected waste allowance and calculate base and bedding cubic yards from explicit layer depths.
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General material planning
Stair Calculator — Riser Height, Tread Depth & Stringer Geometry
Calculate equal riser height, tread depth, tread count, stair angle and straight stringer length from total rise, total run and a chosen number of risers.
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General material planning
Rectangle Diagonal Calculator — Square-Up & Pythagorean Check
Calculate the corner-to-corner diagonal of a rectangle from length and width, then optionally compare a field-measured diagonal with the theoretical value.
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Electrical & engineering
kVA to Amps Calculator — Single & Three Phase
Convert apparent power in kVA to current using voltage and phase configuration, with separate balanced three-phase line-to-line and line-to-neutral voltage formulas.
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Electrical & engineering
Three-Phase Power Calculator — kW, kVA, kVAR & Power Factor
Calculate balanced three-phase apparent, real and reactive power from line-to-line voltage, current and power factor, with phase angle shown for the simplified power triangle.
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Electrical & engineering
VA to Watts Calculator — Apparent vs Real Power
Convert volt-amperes to watts or watts to VA using an explicit power factor, while keeping apparent power and real power separate instead of treating them as interchangeable.
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Electrical & engineering
Demand Factor Calculator — Maximum Demand, Connected Load & Design Current
Calculate electrical demand factor, maximum demand, apparent demand and single- or three-phase design current from connected load with transparent working.
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Electrical & engineering
Generator Efficiency Calculator — Shaft Input, Electrical Output & Losses
Calculate generator or alternator conversion efficiency, total power loss, loss percentage and daily loss energy from measured shaft input and electrical output.
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Electrical & engineering
Generator Voltage Dip Calculator — Motor Starting kVA & Xd″
Estimate initial generator voltage dip from motor starting kVA, genset kVA and alternator subtransient reactance, with remaining voltage and target starting-kVA capacity.
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Electrical & engineering
Generator Sizing Calculator — kW, kVA & Motor Starting Load
Estimate generator kVA from simultaneous running kW, power factor, the largest motor starting kVA, headroom and an explicit derating factor, with single- or three-phase current.
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Electrical & engineering
Generator Fuel Consumption Calculator — L/h, Runtime & Cost
Calculate generator fuel burn from actual electrical load and a manufacturer or measured specific fuel consumption value, then estimate litres, US gallons, tank runtime and fuel cost.
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Electrical & engineering
Generator Load Bank Calculator — kW, kVAR, kVA & Amps
Size resistive and inductive load-bank capacity for a generator test from nameplate kW, rated power factor, target load percentage, voltage and phase.
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Electrical & engineering
Transformer Parallel Load Sharing Calculator — kVA & Impedance
Calculate how two compatible transformers share a parallel kVA load from their ratings and percent impedances, including loading percentages and the bank limit before either unit reaches nameplate kVA.
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Electrical & engineering
Transformer Impedance Calculator — %Z, Ohms, Per-Unit & Fault Level
Convert transformer percent impedance into per-unit and ohms on the selected winding base, with rated current and transformer-only terminal fault-current context.
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Electrical & engineering
Transformer Fault Current Calculator — kA from kVA & %Z
Estimate transformer-limited secondary terminal short-circuit current from transformer kVA, secondary voltage and actual nameplate percent impedance, with rated amps, fault multiplier, MVA and impedance cross-checks.
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Electrical & engineering
Transformer Inrush Current Calculator — Rated Amps & Energization Estimate
Estimate transformer rated current, magnetizing inrush current and equivalent energization kVA from kVA, voltage, phase and a documented inrush multiple.
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Electrical & engineering
Motor Starting Current Calculator — DOL, Star-Delta & Starter Comparison
Estimate AC motor starting current and starting kVA from full-load current and locked-rotor multiple, with DOL, star-delta, autotransformer and soft-starter methods.
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Electrical & engineering
Motor Torque Calculator — Torque, Power & RPM
Calculate electric motor shaft torque, mechanical power or RPM from any two operating-point values, with N·m, lb·ft, kW and mechanical horsepower results.
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Electrical & engineering
Transformer Voltage Regulation Calculator — Measured & R/X Method
Calculate transformer voltage regulation from no-load and loaded voltage, or estimate it from resistance, reactance, power factor and load with lagging/leading handling.
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Electrical & engineering
Transformer All-Day Efficiency Calculator — 24-Hour Load Profile
Calculate transformer all-day energy efficiency from a multi-period load profile, core loss and full-load copper loss, with kWh loss breakdown and duty-cycle diagnostics.
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Electrical & engineering
Transformer Efficiency Calculator — Load, Core & Copper Losses
Calculate transformer efficiency at partial load from rated kVA, power factor, core loss and full-load copper loss, with maximum-efficiency loading and 25–100% scenarios.
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Electrical & engineering
Power Factor Correction Calculator — Capacitor kVAR & Current Reduction
Calculate capacitor-bank kVAR to raise a lagging load from its measured power factor to a target, with before/after kVAR, kVA and optional line-current comparison.
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Electrical & engineering
Motor Slip Calculator — Synchronous Speed, RPM & Rotor Frequency
Calculate induction-motor synchronous speed, slip RPM, slip percent and rotor electrical frequency from supply frequency, pole count and measured shaft RPM, with optional nameplate comparison.
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Electrical & engineering
Voltage Unbalance Calculator — 3-Phase NEMA Method
Calculate three-phase percent voltage unbalance from three line-to-line readings using the NEMA maximum-deviation-from-average method, with phase diagnostics and optional nominal-voltage comparison.
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Electrical & engineering
Current Unbalance Calculator — 3-Phase Maximum-Deviation Method
Calculate three-phase current unbalance from Ia, Ib and Ic using maximum deviation from average, with worst-phase diagnostics, spread and an editable review limit.
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Electrical & engineering
Conduit Offset Calculator — Bend Spacing, Shrink & Marks
Calculate equal-angle conduit offset bend spacing and published field shrink from Greenlee-style multiplier constants, with optional bend-mark and available-length checks.
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Electrical & engineering
Ampacity Derating Calculator — Temperature & Conductor Adjustment
Apply ambient-temperature correction and current-carrying-conductor adjustment to an entered starting ampacity, then compare an optional terminal ceiling and load.
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Electrical & engineering
Wireway Fill Calculator — 20% Fill & >30 Conductor Check
Calculate metal or nonmetallic wireway conductor fill against the 20% interior-area rule, minimum required area, >30 current-carrying-conductor flag and optional splice/tap point check.
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Electrical & engineering
Pull Box Sizing Calculator — NEC 314.28 Straight, Angle & U Pulls
Calculate minimum pull-box and junction-box dimensions for 4 AWG and larger conductors using NEC 314.28 straight-pull, angle/U-pull and same-conductor raceway-spacing rules.
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Electrical & engineering
Electrical Box Fill Calculator — NEC 314.16 Volume Check
Calculate electrical outlet, device and junction-box fill using NEC 314.16 conductor allowances, device yokes, internal clamps, supports, grounding conductors and 2023 terminal blocks.
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Electrical & engineering
Cable Pulling Tension Calculator — Bend & Sidewall Pressure
Estimate cable pulling tension through straight conduit and a bend, compare pull direction, and screen sidewall pressure against manufacturer-entered limits.
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Electrical & engineering
Cable Drum Capacity Calculator — Reel Length & Fill
Estimate cable length on a reel or drum from flange, barrel, winding width, cable OD, edge clearance and packing factor, with reverse flange sizing.
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Electrical & engineering
Conduit Fill Calculator — Wire & Cable Raceway Fill
Calculate conduit fill from actual cable outside diameters and raceway inside diameter, check 53/31/40% conductor-count limits or a custom limit, and reverse-solve minimum ideal ID.
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General material planning
Bend Allowance Calculator — K-Factor, Deduction & Flat Length
Calculate sheet-metal bend allowance, outside setback, bend deduction and single-bend flat length in mm or inches, with reverse K-factor calibration.
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General material planning
Duct Weight Calculator — HVAC Sheet Metal kg/m & Total
Calculate rectangular or round HVAC duct sheet-metal weight per metre and total project mass from dimensions, thickness, density and fabrication allowance.
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Electrical & engineering
Cable Ladder Weight Calculator — kg/m & Project Mass
Estimate cable ladder self-weight from two side-rail linear masses, rung linear mass, ladder width and rung spacing; compare the result with manufacturer kg/m.
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Electrical & engineering
Cable Tray Weight Calculator — Perforated Tray kg/m
Estimate straight perforated or solid-bottom sheet-metal cable tray kg/m and project mass from width, side height, thickness, density and entered perforation.
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Electrical & engineering
Busbar Weight Calculator: Copper & Aluminium kg/m
A 100 × 10 mm copper busbar weighs 8.96 kg/m and the same aluminium bar 2.70 kg/m. Enter any width, thickness and length for kg/m, lb/ft and total mass.
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Electrical & engineering
Copper Wire Weight Calculator — g/m, kg/km & Total Copper Mass
Calculate bare copper conductor weight from cross-sectional area or diameter. Get g/m, kg/km, total copper mass, cost, reverse run count and manufacturer variance.
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Everyday math
Steel Grating Weight Calculator — kg/m², Panel & Project Weight
Estimate welded steel bar grating weight from bearing-bar geometry and pitch. Calculate kg/m², panel/project mass, cost, reverse panel count and supplier variance.
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Everyday math
Expanded Metal Weight Calculator — kg/m², Sheet Weight & Open Area
Estimate expanded metal mesh weight from SWD, strand width, thickness and density. Calculate kg/m², sheet/order mass, open-area estimate, cost and supplier variance.
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Everyday math
Z Section Weight Calculator — Z Purlin kg/m, lb/ft & Total Weight
Estimate cold-formed Z-section or Z-purlin weight from web, flange, lip, thickness and density. Compare supplier kg/m, plan orders and reverse-solve quantity.
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Everyday math
Tee Section Weight Calculator — T-Bar kg/m, lb/ft & Total Weight
Calculate ideal steel tee or T-bar weight from depth, flange width, web/flange thickness and density. Compare published kg/m, estimate orders and reverse-solve quantity.
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Everyday math
I-Beam Weight Calculator — kg/m, lb/ft & Total Beam Weight
Calculate ideal I-beam or H-beam weight from depth, flange width, web/flange thickness and density. Compare published kg/m, estimate batches and reverse-solve quantity.
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Everyday math
Channel Weight Calculator — C/U Channel kg/m & Total Weight
Estimate C-channel or U-channel weight from height, flange width, web/flange thickness and density. Get kg/m, lb/ft, batch mass, cost, reverse quantity and published-weight variance.
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Everyday math
Hex Bar Weight Calculator — kg/m, lb/ft & Total Weight
Calculate solid hexagonal bar weight from across-flats size, length and density. Get kg/m, lb/ft, piece/order mass, cost, reverse piece count and supplier variance.
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Everyday math
Square Bar Weight Calculator — kg/m, lb/ft & Total Weight
Calculate solid square bar and square stock weight from side, length and density. Get kg/m, lb/ft, batch/order mass, cost, reverse piece count and supplier variance.
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Everyday math
Round Bar Weight Calculator — kg/m, lb/ft & Total Weight
Calculate solid round bar, rod and shaft stock weight from diameter, length and density. Get kg/m, lb/ft, batch/order mass, cost, reverse piece count and supplier variance.
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Everyday math
Flat Bar Weight Calculator — kg/m, lb/ft & Batch Weight
Calculate steel, stainless, aluminum or custom flat bar weight from width, thickness and length. Get kg/m, lb/ft, batch/order mass, cost and target-piece reverse solving.
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Everyday math
Angle Weight Calculator — Equal & Unequal Angle kg/m
Calculate angle iron and steel angle weight from both leg sizes, thickness, length and density. Get kg/m, lb/ft, batch mass, cost and target-piece reverse solving.
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Everyday math
Hollow Section Weight Calculator — SHS & RHS kg/m
Calculate square or rectangular hollow section weight from outside dimensions, wall, length and density. Get kg/m, lb/ft, batch mass, cost and supplier variance.
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Everyday math
Rebar Weight Calculator — kg/m, lb/ft, Bars & Tonnes
Calculate theoretical rebar/TMT bar weight from diameter, cut length and quantity. Get kg/m, lb/ft, tonnes, allowance, cost and reverse bars by target mass.
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Everyday math
Pipe Weight Calculator — kg/m, lb/ft & Total Weight
Calculate theoretical round pipe or tube weight from actual OD, wall thickness, length and material density. Get kg/m, lb/ft, batch weight, surface area and reverse wall thickness.
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Everyday math
Metal Plate Weight Calculator — Steel, Aluminum & More
Calculate plate or sheet weight from length, width, thickness and material density. Get kg/lb, batch weight, kg/m², cost, reverse target thickness and measured-density diagnostics.
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Everyday math
Paper Roll Weight Calculator — Reel Weight, Length & GSM Check
Calculate paper roll weight from OD, core OD, width, caliper and GSM. Get roll length, area, net/gross weight, batch weight and measured-roll calibration.
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Everyday math
Label Roll Calculator — Labels Per Roll, Remaining & Diameter
Calculate labels per roll from OD, core, caliper and pitch; estimate labels remaining, multi-lane yield, waste, target diameter and effective caliper from a verified count.
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Everyday math
Shrink Film Size Calculator — Centerfold & Sleeve
Estimate centerfold shrink film width, cut length, batch consumption and sleeve layflat from package dimensions with explicit seal allowances.
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Everyday math
Poly Bag Size Calculator — Flat & Gusseted Bag Fit
Estimate minimum flat or gusseted poly bag dimensions from product width, depth and length with explicit loading and closure allowances.
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Everyday math
Film Weight Calculator — Gauge, Width & Roll Length
Calculate plastic film roll weight, length, width or thickness from density, gauge and dimensions, with GSM, area and optional core weight.
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Everyday math
Coil Weight Calculator — OD, ID, Width & Density
Calculate theoretical steel or metal coil weight from OD, ID, width and density, plus PIW, strip length, run time, capacity utilization and reverse maximum OD.
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Everyday math
Roll Length Calculator — Diameter, Core & Thickness
Estimate paper, film, foil, tape or fabric length from roll diameter, core diameter and thickness, with wraps, area, percent remaining and measured-roll calibration.
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Everyday math
Box Compression Calculator — McKee BCT & Stack Height
Estimate corrugated box compression strength with the simplified McKee equation, then compare an entered safety factor, loaded box weight and planned stack.
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Everyday math
Packing Tape Calculator — Tape per Box & Rolls Needed
Estimate carton sealing tape per box and whole rolls for a batch using center-seam or H-seal geometry, edge overhang, process allowance, roll length and optional roll cost.
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Everyday math
Gross Shipment Weight Calculator — Net, Cartons & Pallets
Calculate cargo gross weight from product quantity, net weight, unit packaging, carton tare, pallets and other packing, with optional container tare and a complete weight audit.
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Everyday math
Box Size Calculator — Product, Padding & Shipping Dimensions
Calculate practical internal and estimated external box dimensions from product size, per-axis padding and wall thickness, with volume fill and editable DIM-weight assumptions.
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Everyday math
Bubble Wrap Calculator — Roll Length & Rolls Needed
Estimate bubble-wrap area, linear roll length, rolls and optional cost from item dimensions, layers, roll width, quantity and a transparent cutting/overlap allowance.
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Everyday math
Stretch Wrap Calculator — Film per Pallet & Rolls Needed
Estimate pallet stretch-film consumption, rolls and cost from load geometry, film overlap, wrap cycles, pre-stretch and waste, then calibrate the plan against measured production use.
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Everyday math
Corrugated Box Weight Calculator — GSM, Blank & Material
Estimate RSC corrugated box weight from finished dimensions, liner and medium GSM, flute take-up, converting allowances and quantity, with every step visible.
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Everyday math
Pieces per Carton Calculator — Units, Fit & Boxes Needed
Calculate how many identical rectangular products fit in a master carton using permitted 90-degree orientations, then check gross-weight capacity, volume fill and cartons needed.
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Everyday math
Package Girth Calculator — Length + Girth for Shipping
Calculate package girth and combined length plus girth from three box dimensions in any order. Compare the result with an optional limit from your current carrier service guide.
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Everyday math
Air Freight Cost Calculator — Chargeable Weight & Quote Breakdown
Estimate air freight from carton dimensions, actual weight and your quoted rate per kg. Compare volumetric vs actual chargeable weight, then model fuel, security, handling, documentation and a minimum charge.
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Measurements
Loading Meter Calculator (LDM) — European Freight & Pallets
Calculate European loading metres (LDM) from cargo or pallet footprint, quantity and safe stack layers. See floor area, trailer utilization, gross weight and optional rate estimate.
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Measurements
LTL Linear Feet Calculator — Pallets, Trailer Space & Rotation
Calculate LTL trailer linear feet from pallet or handling-unit dimensions and quantity. Compare allowed 90° rotation, rows, trailer utilization, gross weight and an optional carrier review threshold.
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Measurements
Freight Density Calculator — lb/ft³, kg/m³ & Estimated NMFC Class
Calculate LTL freight density from packaged dimensions, weight and quantity, then see the matching 2025 NMFC full-density class band with metric and imperial totals.
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Measurements
Container Load Calculator — How Many Boxes Fit in 20ft & 40ft Containers
Calculate how many identical cartons fit in a 20ft, 40ft or 40ft high-cube shipping container. Compare free rotation or upright-only loading, payload, cube utilization and containers required.
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Measurements
CBM Calculator — Carton & Shipping Volume in m³
Calculate carton CBM and total shipment volume from packed dimensions and quantity. Convert mm, cm, m, inches or feet to m³, ft³ and litres, with optional gross-weight and volume-rate planning.
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Measurements
Paper Weight Calculator — GSM, Sheet, Ream & Print Run Weight
Calculate paper weight from GSM, sheet dimensions and quantity. Compare per-sheet, pack, 500-sheet ream, total kg and lb, with custom sizes and packaging.
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Measurements
Dimensional Weight Calculator — Volumetric & Chargeable Weight
Calculate dimensional (volumetric) and chargeable shipping weight from parcel dimensions, actual weight, quantity and an editable DIM divisor.
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Measurements
Pallet Calculator — Boxes per Pallet, TI-HI, Weight & Pallets Needed
Calculate cartons per pallet from box dimensions, pallet footprint, loaded-height and gross-weight limits. Get TI-HI, coverage, limiting constraint and pallets required.
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Time & dates
Date Calculator — Add, Subtract, Difference & Business Days
Calculate the difference between two dates or add and subtract days, weeks, months and years. Compare calendar days with weekday-only business days, see the result weekday and keep the counting convention visible.
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Geometry
Area Calculator — Rectangle, Triangle, Circle, Trapezoid & More
Calculate area for rectangle, square, triangle, circle, trapezoid, parallelogram, ellipse and sector shapes with editable units, converted output units and the substituted formula shown.
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Carpentry & interiors
Drywall Calculator — Sheets, Screws, Tape & Joint Compound
Estimate drywall sheets from room dimensions, openings, ceiling choice, panel size and waste, then add editable planning rates for screws, tape, compound and sheet price.
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Carpentry & interiors
Plywood Calculator — Sheets, Waste & Project Cost
Total up to three rectangular sections, apply an editable waste allowance and estimate whole plywood sheets from the exact sheet dimensions and optional price you enter.
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Carpentry & interiors
Carpet Calculator — Room Area, Waste, Square Yards & Cost
Add up to three rooms, convert square feet to square yards, apply an editable waste allowance and estimate material cost with an optional price per square foot or square yard.
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Carpentry & interiors
Wallpaper Calculator — Strips, Pattern Repeat & Rolls
Estimate wallpaper strips and whole rolls from wall width, height, roll dimensions, pattern repeat, waste and optional roll price, with the drop length shown explicitly.
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Decks, fences & landscape
Fence Calculator — Posts, Panels, Rails & Pickets
Estimate fence posts, bays, panels, rails and pickets from a run length, gate openings, spacing and editable material rates instead of assuming one fence style.
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Concrete & masonry
Post Hole Concrete Calculator — Volume, Bags & Cost
Calculate concrete volume for round post holes from diameter, depth and quantity, then round to whole bags using the bag yield and waste allowance you enter.
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Decks, fences & landscape
Deck Board Calculator — Boards, Fasteners, Linear Feet & Cost
Estimate deck-board rows, linear feet, whole stock boards, board-to-joist intersections, fasteners and optional board cost from deck size, board width, gap, stock length and joist spacing.
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Roofing & exterior
Rafter Length Calculator — Span, Pitch, Overhang & Rafter Count
Calculate common-rafter line length, roof rise, slope factor, angle, overhang extension and an optional rafter count from span, pitch, ridge thickness, building length and spacing.
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Decks, fences & landscape
Paver Base Calculator — Gravel, Bedding Sand, Tons & Bags
Estimate paver sub-base and bedding-layer volume from project dimensions and explicit depths, then convert base volume to adjusted cubic yards, tons and bags using editable compaction, density and bag size.
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Decks, fences & landscape
Polymeric Sand Calculator — Paver Joint Bags & Joint Volume
Estimate polymeric sand bags using product-label coverage or an explicit rectangular-paver joint-volume model with paver size, joint width, fill depth, bag yield, allowance and optional price.
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Concrete & masonry
Concrete Footing Calculator — Round, Square & Rectangular Footings
Calculate concrete volume for round piers, square pads or rectangular/strip footings, multiply by quantity, add an editable allowance and round to whole premix bags from entered bag yield.
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Concrete & masonry
Concrete Steps Calculator — Solid Stair Volume, Bags & Cost
Estimate concrete for a simple solid stair mass from step count, rise, tread and width using a stacked-prism model, with optional landing depth, allowance, bag yield and material cost.
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Concrete & masonry
Brick Calculator — Bricks, Mortar, Cement, Sand & Cost
Estimate bricks for one or more walls after opening deductions, then calculate wet and dry mortar, cement bags, sand volume and optional material cost from actual brick dimensions and mortar-joint inputs.
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Concrete & masonry
Concrete Block Calculator — CMU Blocks, Mortar, Grout, Pallets & Cost
Estimate concrete blocks for a wall after opening deductions, then plan mortar bags, pallets and optional core-fill grout from actual block-face dimensions and editable product coverage, void fraction and bag-yield inputs.
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Roofing & exterior
Asphalt Calculator — Compacted Volume, Tons, Truckloads & Cost
Calculate compacted asphalt volume, base mass, order tonnage, optional loose-volume planning, truckloads and material cost from measured area, finished thickness, entered density and order allowance in imperial or metric units.
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Decks, fences & landscape
Mulch Calculator — Cubic Yards, Bags, Coverage, Weight & Cost
Estimate mulch volume from rectangular, circular or known bed area, then calculate whole bags, bulk quantity, coverage, optional supplier-density weight and bag-versus-bulk material cost in imperial or metric units.
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General material planning
Tank Volume Calculator — Capacity, Partial Fill, Gallons, Litres & Weight
Calculate total and partial-fill volume for rectangular, vertical-cylinder, horizontal-cylinder, horizontal-elliptical, horizontal-capsule and spherical tanks, with litres, US/Imperial gallons, remaining capacity, liquid weight and optional fill/drain time.
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General material planning
Pipe Volume Calculator — Litres, Gallons, Partial Fill, Weight & Fill Time
Calculate pipe internal capacity from actual bore or outside diameter plus wall thickness, including partial horizontal fill, multiple runs, fittings-length allowance, litres/gallons, fluid weight, volume per metre and optional fill/drain time.
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Concrete & masonry
Retaining Wall Calculator — Blocks, Base, Drainage, Pipe & Cost
Estimate retaining-wall blocks, courses, caps, base gravel, drainage rock, drain-pipe allowance, aggregate weight and editable material costs from project dimensions.
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Carpentry & interiors
Board and Batten Calculator — Equal Spacing, Layout Marks & Materials
Lay out board-and-batten walls by target spacing or fixed batten count, then calculate exact clear gaps, on-center spacing, mark positions, linear footage, stock boards, waste and optional cost.
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Carpentry & interiors
Cabinet Door Calculator — Overlay, Inset, Pair Gap & Shaker Cut List
Calculate finished cabinet door dimensions for inset or overlay openings, single or paired doors, then estimate Shaker rail, stile and panel cut sizes from your actual joinery allowances.
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Carpentry & interiors
Wainscoting Calculator — Equal Panel Spacing, Rails, Stiles & Cost
Design symmetrical wainscoting from wall width, height, stile width and target panel width, with exact panel spacing, vertical and horizontal trim footage, stock-board count, waste and optional cost.
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Concrete & masonry
Concrete Block Fill Calculator — CMU Core Volume, Bags & Cost
Estimate CMU core-fill grout or concrete from block count, manufacturer fill volume, filled-cell percentage, placement allowance, bag yield and optional bag price without assuming one universal block void size.
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Concrete & masonry
Rebar Calculator — Slab Grid Bars, Length, Stock Pieces, Weight & Cost
Build a two-direction slab rebar quantity from measured length, width, edge cover and spacing, then estimate total bar length, lap/waste allowance, stock pieces, optional weight and material cost.
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Decks, fences & landscape
Deck Stain Calculator — Surface Area, Coats, Gallons, Containers & Cost
Estimate deck stain or paint from deck, railing and stair surface area, product coverage, coat count, waste allowance and container size, with whole-container rounding and optional cost.
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Roofing & exterior
Asphalt Sealer Calculator — Driveway Gallons, Pails & Material Cost
Calculate driveway or parking-area sealcoat from pavement area, coats, product coverage, allowance and pail size, with label-driven coverage, whole-container rounding and optional cost.
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Roofing & exterior
Siding Calculator — Net Wall Area, Squares, Panels, Waste & Cost
Estimate siding from up to three wall rectangles, openings, waste and actual product coverage, returning net area, siding squares, whole panels/cartons and optional material cost without assuming one panel format.
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Roofing & exterior
Roofing Shingle Calculator — Roof Area, Squares, Bundles & Cost
Estimate asphalt shingles from measured roof area or building footprint plus pitch, then add waste, convert to roofing squares, round field-shingle bundles and optionally estimate material cost.
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Carpentry & interiors
Lumber Weight Calculator — Board Dimensions, Board Feet, Density & Load
Estimate lumber volume and weight from actual board dimensions or total board feet using an editable wood density, with quantity, cubic-foot conversion and optional cost per board foot.
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Decks, fences & landscape
Topsoil Calculator — Cubic Yards, Tons, Bags & Cost
Calculate topsoil volume from area and depth, then compare cubic yards, editable density-based tons, whole bags, settling allowance and optional bag cost.
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Decks, fences & landscape
Compost Calculator — Cubic Yards, Bags, Weight & Cost
Estimate compost for beds or topdressing with depth, repeated areas, allowance, bag volume, editable bulk density and optional bag cost.
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Decks, fences & landscape
Sod Calculator — Lawn Area, Pieces, Pallets, Waste & Cost
Estimate net sod area after openings, add cutting allowance, and convert the order into supplier-specific pieces or pallets with optional pallet cost.
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Decks, fences & landscape
Grass Seed Calculator — Pounds, Bags & Overseeding Rate
Convert lawn area and your chosen label seeding rate into pounds of seed, allowance-adjusted quantity, whole bags and optional cost.
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Decks, fences & landscape
Lawn Fertilizer Calculator — Nitrogen Rate to Product Pounds
Convert a chosen pounds-of-nitrogen-per-1,000-ft² target and fertilizer N analysis into product weight, whole bags and optional material cost.
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Decks, fences & landscape
Raised Bed Soil Calculator — Volume, Bags & Mix Split
Calculate raised-bed fill volume, partial-fill percentage, bag count and an editable compost-versus-base mix split.
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Decks, fences & landscape
Pond Liner Calculator — Sheet Size, Area & Roll Length
Size a rectangular pond liner from pond length, width, maximum depth and edge overlap, then estimate sheet area and roll lanes from an entered roll width.
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Decks, fences & landscape
Firewood Calculator — Stack Volume, Full Cords & Value
Convert measured stacked firewood dimensions into stacked cubic feet, full cords and optional value while keeping ambiguous face-cord terminology separate.
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Decks, fences & landscape
Landscape Fabric Calculator — Square Feet, Roll Coverage & Cost
Turn measured landscape area into allowance-adjusted fabric square footage, whole rolls, purchased coverage and optional roll cost.
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Decks, fences & landscape
Irrigation Runtime Calculator — Inches per Week to Minutes per Zone
Convert a chosen weekly water-depth target and measured sprinkler precipitation rate into weekly runtime and minutes per watering, with explicit efficiency adjustment.
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Electrical & engineering
kW ↔ kVA Calculator — Real & Apparent Power
Convert kW to kVA or kVA to kW with an explicit power factor, plus a reverse check that keeps real and apparent power from being treated as the same quantity.
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Electrical & engineering
Horsepower to Amps Calculator — DC, 1-Phase & 3-Phase
Convert electric horsepower output to estimated input current using voltage, efficiency, phase and power factor, with the input watts and assumptions shown beside the result.
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Electrical & engineering
Ah ↔ Wh Calculator — Battery Charge & Energy
Convert amp-hours to watt-hours or watt-hours to amp-hours using battery voltage, with kWh and mAh equivalents and a reverse check on the same page.
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Electrical & engineering
Battery Runtime Calculator — Wh/Ah, Load, DoD & Efficiency
Estimate battery runtime from Wh or Ah capacity, voltage, load, usable depth of discharge and conversion efficiency, while keeping ideal and adjusted runtime separate.
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Electrical & engineering
Series & Parallel Resistor Calculator — Equivalent Resistance
Calculate equivalent resistance for up to four resistors in series or parallel, with reciprocal working shown and an optional source voltage for total current.
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Electrical & engineering
Series & Parallel Capacitor Calculator — Equivalent Capacitance
Calculate equivalent capacitance for up to four capacitors in series or parallel, with the reciprocal relationship and optional stored-energy estimate from an entered voltage.
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Electrical & engineering
Frequency ↔ Period Calculator — Hz, kHz, MHz, Seconds & More
Convert frequency to period or period to frequency with explicit Hz/kHz/MHz/GHz and s/ms/µs/ns units, reciprocal working, cycles-per-minute context and a reverse check.
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Electrical & engineering
Joules ↔ Watt-Hours Calculator — J, kJ, MJ, Wh & kWh
Convert joules to watt-hours or watt-hours to joules using the exact 3,600 J per Wh relationship, with kJ, MJ, Wh and kWh equivalents plus visible reciprocal working.
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Electrical & engineering
kWh ↔ MJ Calculator — Kilowatt-Hours & Megajoules
Convert kilowatt-hours to megajoules or megajoules to kilowatt-hours with the exact 1 kWh = 3.6 MJ relationship, plus joule, kilojoule and watt-hour equivalents.
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Electrical & engineering
Transformer Turns Ratio Calculator — Solve Voltage or Winding Turns
Solve an ideal transformer for primary voltage, secondary voltage, primary turns or secondary turns from the other three values, with turns ratio, voltage ratio and ideal current-ratio context.
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Electrical & engineering
Transformer kVA Calculator — Single & Three-Phase Current
Calculate transformer kVA from voltage and current or calculate ideal primary and secondary full-load current from a kVA rating, with single-phase and balanced three-phase formulas kept explicit.
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Electrical & engineering
RC Time Constant Calculator — Solve τ, R or C + Cutoff & Timing
Calculate RC time constant from resistance and capacitance or solve backward for resistance or capacitance from a target tau, with five-tau settling, first-order cutoff and charge/discharge timing.
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Electrical & engineering
LED Resistor Calculator — E12/E24 Value, Color Code & Power
Calculate a simple DC LED current-limiting resistor, round upward to E12/E24, recalculate actual current and power, and show the selected resistor’s standard 4-band color code.
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Electrical & engineering
Reactance Calculator — Inductive XL, Capacitive XC & LC Resonance
Calculate inductive or capacitive reactance, reverse-solve frequency or component value, or find ideal LC resonant frequency with engineering-unit inputs and visible formulas.
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Electrical & engineering
Internal Resistance Calculator — Battery Load Test, Two Points & Voltage Sag
Estimate a source or battery internal resistance from open-circuit and loaded voltage, from two load points, or run the internal-resistance model forward to check sag, loss and efficiency.
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Measurements
Pressure Converter — PSI, Bar, kPa, MPa, atm, Torr & mmHg
Convert pressure instantly between Pa, hPa, kPa, MPa, GPa, bar, mbar, psi, ksi, atm, Torr, mmHg, inHg and kgf/cm², with every equivalent, the direct factor, adjustable precision and gauge-vs-absolute guidance.
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Measurements
Torque Unit Converter — N·m, lb·ft, lb·in, oz·in & kgf·m
Convert torque between N·m, kN·m, mN·m, lbf·ft, lbf·in, ozf·in, kgf·m, kgf·cm and gf·cm with every equivalent, adjustable precision and a direct conversion factor.
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Measurements
Force Converter — Newtons, kN, lbf, kgf, Kip & Dyne
Convert force between N, mN, kN, MN, lbf, ozf, kip, kgf, gf, dyne, poundal and US ton-force, with all equivalents, adjustable precision and clear mass-versus-force guidance.
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Measurements
Energy Unit Converter — J, kJ, MJ, kWh, Calories, BTU & eV
Convert energy between joules, kJ, MJ, GJ, Wh, kWh, MWh, calories, food Calories, BTU, electronvolts, ft·lbf and ergs, with all equivalents, scientific notation and clear energy-vs-power context.
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Measurements
Power Unit Converter — W, kW, MW, HP, PS, BTU/h & Refrigeration Tons
Convert power between W, mW, kW, MW, GW, mechanical hp, metric PS, BTU/h, kcal/h, refrigeration tons and ft·lbf/s, with all equivalents and explicit power-vs-energy guidance.
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Measurements
Angle Converter — Degrees, Radians, Gradians, Turns, Arcmin & Arcsec
Convert angles between radians, milliradians, degrees, gradians/gons, turns, arcminutes and arcseconds with all equivalents, exact circle relationships, swap and adjustable precision.
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Measurements
Data Rate Converter — Mbps, MB/s, Gbps, GB/s, Mib/s & MiB/s
Convert data transfer rates between decimal bit/byte units and binary Kib/Mib/Gib units, including Mbps↔MB/s and Gbps↔GB/s, with all equivalents plus GB/hour and TB/day throughput context.
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Statistics
Statistics Calculator — Mean, Median, Mode, Quartiles, Variance & Standard Deviation
Paste a dataset and calculate count, sum, mean, median, modes, min/max/range, Tukey quartiles, IQR, sample/population variance and standard deviation, standard error, coefficient of variation, skewness, excess kurtosis, outlier fences and a frequency table.
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Statistics
Standard Deviation Calculator — Sample & Population Variance with Steps
Calculate sample or population standard deviation from pasted data with mean, variance, squared-deviation sum, standard error, coefficient of variation, Tukey outliers and a row-by-row deviation and z-score table.
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Statistics
Weighted Average Calculator — Values, Weights, Contributions & Plain Average
Paste value-and-weight rows to calculate the weighted mean, weighted sum, total weight, plain average, weighting shift and each row’s normalized weight percentage, product and contribution, without requiring weights to total 100.
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Statistics
Correlation Calculator — Pearson & Spearman with Paired-Data Working
Paste paired X and Y data to calculate Pearson correlation or Spearman rank correlation with R², covariance, best-fit slope, pair count and an auditable row table.
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Statistics
Covariance Calculator — Sample & Population Covariance with Correlation
Calculate sample or population covariance from two paired datasets, with means, cross-deviation sum, standard deviations, Pearson correlation and row-by-row working.
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Statistics
Z-Score Calculator — Standardize or Reverse-Solve x, Mean & SD
Calculate z = (x − mean) / SD or reverse-solve the raw value, mean or standard deviation, with normal-distribution percentile context and substituted steps.
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Statistics
Confidence Interval Calculator — Mean (z/t) & Proportion with Steps
Calculate 90%, 95% or 99% confidence intervals for a mean with known population SD, a mean with sample SD using t, or a proportion using the Wilson interval.
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Statistics
Frequency Distribution Calculator — Frequency, Relative & Cumulative Tables
Paste raw data to build ungrouped or grouped frequency distributions with count, relative frequency, cumulative frequency, cumulative percentage, class midpoint and a check against the original n.
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Statistics
Linear Regression Calculator — Best-Fit Line, R², Correlation & Residuals
Fit a simple least-squares line to paired X/Y data and calculate slope, intercept, Pearson r, R², prediction, residuals and the sums used in the regression.
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Fractions
Fraction Calculator — Add, Subtract, Multiply & Divide
Calculate two fractions with exact integer arithmetic, simplify the result, show improper and mixed-number forms, and follow the common-denominator or reciprocal steps.
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Fractions
Decimal ↔ Fraction Calculator — Exact Steps & Mixed Number
Convert a terminating decimal to an exact simplified fraction or convert a fraction back to decimal, with the place-value fraction, GCD reduction and mixed-number form shown.
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Fractions
Fraction Simplifier — Reduce to Lowest Terms
Reduce a fraction to lowest terms using the greatest common divisor, normalize the sign, and show decimal and mixed-number forms with the reduction step.
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Fractions
Mixed Number ↔ Improper Fraction Calculator
Convert mixed numbers to improper fractions or improper fractions back to mixed form, with sign handling, simplification and the multiplication-plus-remainder steps shown.
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Fractions
Inch Fraction Calculator — Decimal, Millimeters & Tape-Measure Fractions
Round decimal inches or millimeters to the nearest 1/2 through 1/64 inch, show feet-and-inches form, error from the rounded mark and reverse fraction-to-decimal values.
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Geometry
Pythagorean Theorem Calculator — Solve a Leg, Hypotenuse & Area
Solve a right-triangle leg or hypotenuse from two known sides, show the substituted equation, area, perimeter and acute angles, and reject impossible side combinations.
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Geometry
Triangle Calculator — Sides, Angles, Area & Perimeter
Solve a triangle from three side lengths using Heron’s formula and the law of cosines, with validity checks, angle sum, area, perimeter and triangle-type labels.
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Geometry
Circle Calculator — Radius, Diameter, Circumference & Area
Start with radius, diameter, circumference or area and solve the other circle measurements.
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Geometry
Rectangle Calculator — Area, Perimeter & Diagonal
Calculate rectangle area, perimeter, diagonal and aspect ratio, and compare an optional measured diagonal with the calculated one to check that a layout is square.
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Geometry
Perimeter Calculator — Rectangle, Square, Triangle & Circle
Calculate the perimeter of a rectangle, square or triangle, or the circumference of a circle, with the substituted working.
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Geometry
Volume & Cubic Yard Calculator — Shapes, yd³, ft³, m³, Weight & Cost
Calculate box, cylinder, sphere or area-by-depth volume and instantly convert the result to cubic feet, cubic yards and cubic metres, with optional waste, material density, weight and bulk cost.
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Geometry
Slope Calculator — Rise, Run, Percent, Angle & Ratio
Convert rise and run into decimal slope, percent grade, angle, ratio and straight-line length.
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Screen & media
PPI Calculator — Pixel Density, Pixel Pitch & Megapixels
Calculate display PPI from pixel resolution and physical diagonal, with diagonal pixels, pixel pitch, aspect ratio, megapixels and common density context shown together.
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Screen & media
Screen Size Calculator — Width, Height & Area from Diagonal
Convert a display diagonal and aspect ratio into physical width, height, area and perimeter, with presets for common 16:9, 16:10, 21:9, 4:3 and 3:2 screens.
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Screen & media
Aspect Ratio Calculator — Simplify, Resize & Letterbox
Simplify pixel dimensions to an aspect ratio, calculate a proportional missing dimension and measure letterbox/pillarbox padding when fitting media inside a target frame.
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Screen & media
Video Bitrate Calculator — Target File Size, Duration & Audio
Calculate the average video bitrate required to hit a target file size after reserving an editable audio bitrate, with total bitrate and overhead margin kept visible.
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Screen & media
Video File Size Calculator — Bitrate × Duration
Estimate video file size from video bitrate, audio bitrate and duration, with MB/MiB/GB/GiB outputs and a reverse target-size link for compression planning.
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Money & business
Credit Card Payoff Calculator — Payment, Months & Interest
Model a credit-card payoff from balance and APR, solve either the payoff time from a fixed payment or the payment required for a target month, and include recurring spending and annual fees.
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Money & business
Debt-to-Income Ratio Calculator — Front-End, Back-End & Scenario DTI
Calculate housing and total debt-to-income ratios from itemized monthly obligations, then add a proposed new payment to see the scenario DTI without applying a one-size-fits-all approval threshold.
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Money & business
Investment Fee Calculator — Fee Drag vs No-Fee Growth
Compare a contribution-based investment projection with and without sales load, annual asset fees and an ending redemption fee, with the fee assumptions and return model kept editable.
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Money & business
NPV Calculator — Net Present Value of Irregular Cash Flows
Calculate net present value for a time-zero cash flow and an irregular series of later cash flows, with a per-period present-value table that exposes every discounted term.
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Money & business
IRR Calculator — Internal Rate of Return from Cash Flows
Estimate internal rate of return from a time-zero amount and irregular per-period cash flows, show NPV at an optional hurdle rate, and warn when the cash-flow pattern can produce multiple IRRs.
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Money & business
Commission Calculator — Simple, Tiered & Base Pay
Calculate a simple percentage commission or a progressive three-tier commission from revenue or gross profit, then include optional base pay and see the effective commission rate.
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Everyday math
Recipe Scaling Calculator — Fractions, Servings & Ingredient List
Scale a pasted ingredient list from original to target servings, parse common decimals, fractions, mixed numbers and Unicode fractions, and return practical scaled quantities without pretending cooking time scales linearly.
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Everyday math
Fuel Cost Calculator — Trip Fuel, Cost & Cost per Person
Estimate trip fuel and cost from distance, trip type, repeated trips, fuel economy in km/L, L/100 km or US MPG, and fuel price per liter or US gallon, with optional fixed trip costs.
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Statistics
Sample Size Calculator — Proportion, Mean, FPC & Response Rate
Calculate a required sample for a proportion or mean from confidence and margin of error, with optional finite-population correction, design effect and expected response rate to estimate invitations.
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Statistics
Margin of Error Calculator — Proportion or Mean with FPC
Calculate a z-based margin of error for a proportion or mean from sample size and confidence, with optional finite-population correction and a transparent conservative p = 50% option.
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Statistics
Combinations & Permutations Calculator — Exact nCr, nPr & Factorial
Calculate combinations nCr and permutations nPr together with exact integer arithmetic, factorial context and a clear explanation of when order matters.
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Statistics
Probability Calculator — AND, OR, Conditional & Complement
Calculate two-event probability with independent AND/OR, general overlap, conditional probability and complements, including consistency checks and visible working.
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Everyday math
Tire Size Calculator — Compare Diameter, Clearance & Speedometer Error
Compare two P-metric tire sizes side by side for sidewall, diameter, circumference, axle clearance and theoretical speedometer error.
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Everyday math
Gear Ratio RPM Calculator — Speed, Cruise RPM & Overall Ratio
Solve theoretical road speed from RPM or engine RPM from road speed using transmission ratio, final drive and tire diameter, with overall gearing kept visible.
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Everyday math
Dew Point Calculator — °C/°F, RH & Reverse Solve
Calculate dew point, relative humidity or air temperature with the Alduchov–Eskridge Magnus approximation. Work in °C or °F and inspect dew-point depression, vapor pressure, reverse solving and humidity scenarios.
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Everyday math
Heat Index Calculator — NWS Feels-Like Temperature
Calculate feels-like temperature with the full NWS heat-index decision procedure: simple screening formula, Rothfusz regression when applicable, and the official low/high-humidity adjustments. Results show °C and °F, method branch, adjustment and heat-category context.
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Everyday math
Wind Chill Calculator — NWS Formula, °C/°F & Wind Units
Calculate NWS wind chill from air temperature and wind speed with °C/°F plus mph, km/h, m/s or knots. The calculator enforces the official weather-use range and shows substituted working and wind-speed scenarios.
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Everyday math
Density Calculator — Solve Density, Mass or Volume + Units
Solve density, mass or volume from any two known values with SI, metric and US customary units. See equivalent density units, specific gravity and substituted working.
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Everyday math
Molarity Calculator — Concentration, Moles, Mass or Volume
Solve amount concentration (molarity), moles, solute mass or final solution volume. Supports M, mM and µM plus mass-based calculations using molar mass.
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Everyday math
Running Pace Calculator — Pace, Time, Distance & Race Splits
Solve running pace, finish time or distance with km/mile units. See min/km, min/mile, km/h, mph and constant-pace splits for common race distances.
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Everyday math
Kinetic Energy Calculator — Solve Energy, Mass or Speed + Units
Solve classical translational kinetic energy, mass or speed from any two values. Convert mass, speed and energy units and see velocity-squared sensitivity.
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Everyday math
Momentum Calculator — Solve p, Mass or Velocity + Units
Solve linear momentum, mass or signed velocity using p = mv. Convert common mass, velocity and momentum units and inspect impulse and kinetic-energy context.
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Everyday math
Wavelength & Frequency Calculator — Solve λ, f or Wave Speed
Solve wavelength, frequency or propagation speed with unit conversion and optional medium presets for sound/light examples. Includes period and wave-number diagnostics.
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Everyday math
Centripetal Force Calculator — Solve Force, Mass, Speed or Radius + RPM
Solve centripetal force, mass, tangential speed or radius for uniform circular motion. Use linear speed, angular speed, RPM or period and see acceleration, g-force, angular speed and substituted working.
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Money & business
Loan Payoff Calculator — Extra Payments, Lump Sum & Amortization
Compare a scheduled loan with recurring extra principal and a timed lump-sum payment. See the full amortization schedule, payoff time, interest saved and time saved without creating separate thin mortgage or auto-loan copies.
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Money & business
Unit Price Calculator — Compare Price per Unit
Normalize mixed package sizes and units, rank shopping options by unit price and see the savings or premium versus the lowest-cost option.
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Money & business
Rule of 72 Calculator — Doubling Time & Exact Comparison
Estimate doubling time with the Rule of 72, compare it with the exact logarithmic result and reverse-solve the rate for a target doubling time.
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Money & business
Pay Raise Calculator — New Pay, Raise % & Real Change
Calculate new pay from a raise percentage or recover the raise percentage from old and new pay, with optional inflation context for purchasing-power comparison.
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Money & business
Savings Withdrawal Calculator — Drawdown Duration & Ending Balance
Model level withdrawals from a savings balance under an entered constant return assumption to estimate duration, ending balance and drawdown behavior.
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Electrical & engineering
Voltage Drop Calculator — Forward & Reverse Electrical Solve
Calculate voltage drop and percentage drop, or reverse-solve maximum run, current or conductor area from explicit resistivity and circuit assumptions.
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Electrical & engineering
Pump Power Calculator — Flow, Head, Density & Efficiency
Calculate hydraulic power and estimated pump input power from flow, total head, fluid density and overall efficiency.
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Electrical & engineering
Water Tank Volume Calculator — Liters, Gallons & Fill Level
Calculate rectangular or vertical cylindrical tank capacity and filled volume from inside dimensions, with liters, cubic meters and US gallons.
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Electrical & engineering
Concrete Weight Calculator — Volume, Density & Total Mass
Calculate concrete volume and estimated weight from slab dimensions and an editable density instead of assuming one universal mix weight.
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Electrical & engineering
Solar Panel Output Calculator — Daily & Monthly Energy Estimate
Estimate daily and monthly solar energy from array watts, peak-sun-hours and an explicit system-efficiency percentage.
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Electrical & engineering
Cylinder Volume Calculator — Volume, Surface Area & Fill
Calculate solid cylinder volume, lateral area, total surface area and optional filled volume from radius or diameter and height.
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Electrical & engineering
Sand Calculator — Volume, Weight & Bags
Estimate sand volume, mass and bags from length, width, depth, density and bag size with an optional waste allowance.
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Electrical & engineering
Post Hole Concrete Calculator — Volume & Bags
Calculate concrete around round posts from hole diameter, post diameter, embedment depth and post count, then estimate bags.
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Electrical & engineering
Resistor Color Code Calculator — 4 & 5 Band Values
Decode 4-band and 5-band resistor color codes into resistance and tolerance with independent significant-digit, multiplier and tolerance selections.
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Electrical & engineering
Capacitor Energy Calculator — Joules, Charge & Voltage
Calculate stored capacitor energy and charge from capacitance and voltage, with common capacitance unit conversion.
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Electrical & engineering
Roofing Material Calculator — Squares, Shingles & Underlayment
Turn footprint and roof pitch into sloped roof area, then estimate roofing squares, shingle bundles and underlayment rolls with explicit waste.
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Electrical & engineering
Lumber Cut Calculator — Pieces, Kerf & Board Length
Estimate how many equal-length pieces fit in stock boards while accounting for saw kerf, then calculate stock-board count and offcut.
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Electrical & engineering
Inductive Reactance Calculator — XL from Frequency & Inductance
Calculate ideal inductor reactance from frequency and inductance with Hz/kHz and H/mH/µH input units.
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Electrical & engineering
Capacitive Reactance Calculator — XC from Frequency & Capacitance
Calculate ideal capacitor reactance from frequency and capacitance with common frequency and capacitance units.
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Electrical & engineering
LC Resonant Frequency Calculator — Frequency, L & C
Calculate ideal LC resonant frequency from inductance and capacitance with common engineering input units.
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Electrical & engineering
Three-Phase Energy Calculator — kW, kWh & Current
Calculate balanced three-phase real power and energy from line voltage, line current, power factor and time, or reverse-solve current from target kW.
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Electrical & engineering
Motor Current Calculator — kW/HP to Full-Load Amps
Estimate single-phase or three-phase AC motor full-load current from shaft power, voltage, power factor and efficiency, with input kW, apparent kVA and adjustable starting-current context.
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Electrical & engineering
Frequency & Wavelength Calculator — Hz, Period and Wave Speed
Solve frequency, wavelength or period from one known value and a configurable wave speed, with engineering-friendly Hz, kHz, MHz, GHz, m, cm, mm and nm conversions.
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Electrical & engineering
Voltage Divider Calculator — Output, Loaded Divider & Current
Calculate unloaded or loaded voltage-divider output, source current, equivalent lower resistance and resistor/load power from explicit circuit values.
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Electrical & engineering
RC Filter Calculator — Cutoff, Gain, Phase & Time Constant
Analyze an ideal first-order RC low-pass or high-pass response from resistance, capacitance and signal frequency with engineering-unit inputs.
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Electrical & engineering
RL Filter Calculator — Cutoff, Reactance & Time Constant
Calculate first-order RL cutoff frequency, inductive reactance, time constant and ideal low-pass/high-pass magnitude at a test frequency.
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Electrical & engineering
Series RLC Impedance Calculator — Magnitude, Phase & Resonance
Solve ideal series RLC inductive/capacitive reactance, impedance magnitude, phase angle and resonant frequency from R, L, C and frequency.
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Electrical & engineering
Parallel RLC Impedance Calculator — Admittance, Phase & Resonance
Calculate ideal parallel RLC admittance, impedance magnitude, impedance phase and resonant frequency from R, L, C and frequency.
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Electrical & engineering
Wheatstone Bridge Calculator — Balance, Output Voltage & Unknown Resistance
Calculate Wheatstone bridge differential midpoint voltage from four entered arms and report the balanced R4 implied by R1, R2 and R3.
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Electrical & engineering
Op-Amp Gain Calculator — Inverting & Non-Inverting Output
Calculate ideal closed-loop op-amp gain and ideal output voltage for inverting or non-inverting resistor networks.
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Electrical & engineering
Inductor Energy Calculator — Joules, Current & Magnetic Storage
Calculate ideal magnetic energy stored in an inductor from current and inductance entered in mH, with results in joules, millijoules and microjoules.
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Electrical & engineering
Zener Resistor Calculator — Series Resistor, Current & Power
Size a basic Zener shunt-regulator series resistor from supply, Zener voltage, load current and target Zener current, then estimate resistor and diode power.
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Electrical & engineering
555 Timer Calculator — Astable Frequency, Duty Cycle & Pulse Timing
Calculate classic 555 astable frequency, period, high/low time and duty cycle from R1, R2 and C using deterministic ideal timing equations.
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Electrical & engineering
RMS Voltage Calculator — Waveform, Peak, DC Offset & Crest Factor
Convert peak AC voltage to RMS for sine, square, triangle, sawtooth and rectified waveforms, then combine an independent DC offset by root-sum-square. See AC RMS, total RMS, peak-to-peak and crest factor.
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Electrical & engineering
Decibel Gain Calculator — Voltage, Power, Ratio & Reverse dB
Convert voltage/amplitude or power ratios to decibels and reverse any positive, zero or negative dB value back to its linear ratio.
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Electrical & engineering
MOSFET Gate Drive Calculator — Gate Current, Power & Switching Time
Estimate MOSFET gate-drive average current, drive power, peak current and a charge-based switching-time estimate from total gate charge, drive voltage, frequency and entered gate resistance.
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Electrical & engineering
PCB Trace Width Calculator — IPC-2221 Current, Copper & Temperature Rise
Estimate PCB copper trace width and cross-sectional area from current, copper weight, allowed temperature rise and external/internal layer position using the IPC-2221 empirical relationship.
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Electrical & engineering
ADC Resolution Calculator — LSB Size, Quantization & Code
Calculate ideal ADC LSB size, code count, quantization uncertainty and saturated output code from bit depth, reference voltage and input voltage.
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Electrical & engineering
Capacitor Discharge Calculator — RC Voltage, Current & Time Constant
Calculate exponential capacitor-discharge voltage and current at an entered elapsed time, plus the RC time constant and five-time-constant reference.
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Electrical & engineering
Buck Converter Calculator — Duty Cycle, Input Current & Ideal Power
Estimate ideal buck-converter duty cycle, output power, input current and conversion loss from input/output voltage, output current and efficiency.
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Electrical & engineering
Boost Converter Calculator — Duty Cycle, Input Current & Ideal Power
Estimate ideal boost-converter duty cycle, output power, input current and conversion loss from input/output voltage, load current and efficiency.
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Electrical & engineering
Resistor Thermal Noise Calculator — Johnson Noise Voltage & Density
Calculate Johnson-Nyquist RMS noise voltage and spectral density from resistance, absolute temperature and bandwidth.
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Electrical & engineering
Skin Depth Calculator — Frequency, Conductivity & Permeability
Calculate electromagnetic skin depth from frequency, conductivity in MS/m and relative permeability for a homogeneous conductor.
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Electrical & engineering
Op-Amp Slew Rate Calculator — Full-Power Bandwidth & Required SR
Calculate required slew rate from sine-wave frequency and peak voltage, and full-power bandwidth from available slew rate and peak voltage.
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Electrical & engineering
Coaxial Cable Impedance Calculator — Geometry & Dielectric
Estimate coax characteristic impedance from inner-conductor diameter, shield inner diameter and relative permittivity.
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Electrical & engineering
Speaker Crossover Calculator — 1st-Order High-Pass & Low-Pass
Calculate ideal first-order passive speaker crossover capacitor and inductor values from nominal impedance and crossover frequency.
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Electrical & engineering
Primer Tm Calculator — Melting Temperature, GC% & Primer Pair Check
Estimate DNA primer melting temperature from sequence, compare forward and reverse primers, inspect GC content and ΔTm, and see the calculation method used.
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Electrical & engineering
PCR Annealing Temperature Calculator — Primer Pair, ΔTm & Gradient Range
Estimate a practical PCR annealing-temperature starting point from forward and reverse primer Tm values, flag mismatched primer pairs and generate a gradient range for empirical optimization.
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Electrical & engineering
Dilution Calculator — Solve Any C₁V₁=C₂V₂ Unknown
Solve any one unknown in C₁V₁=C₂V₂ and calculate diluent volume when both stock and final volumes are known. Use consistent concentration and volume units across the equation.
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Electrical & engineering
Serial Dilution Calculator — Concentration & Pipetting Table
Plan repeated serial dilutions from a starting concentration, dilution factor, number of steps and the final volume you want to retain in every tube. The pipetting table automatically prepares enough upstream volume for onward transfers.
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Electrical & engineering
PCR Master Mix Calculator — Reactions, Overage & Shared Mix Volume
Scale aggregate shared PCR mix volume across multiple reactions from reaction volume, template volume and configurable overage, while keeping template volume separate.
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Electrical & engineering
DNA Copy Number Calculator — ng/µL, bp, Copies/µL & qPCR Copies
Convert dsDNA or ssDNA mass concentration and fragment length into molecules per microlitre, total molecules and qPCR template copies per reaction. Optional exact molecular weight overrides the base-pair estimate.
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Electrical & engineering
DNA Ligation Calculator — Insert:Vector Molar Ratio, ng, fmol & Pipetting Volumes
Calculate required insert DNA mass from vector and insert lengths, compare the actual insert:vector molar ratio, convert both fragments to femtomoles and optionally calculate pipetting volumes from stock concentrations.
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Electrical & engineering
DNA Concentration Calculator — A260, Purity Ratios, ng/µL & nM
Convert A260 absorbance to dsDNA, ssDNA or RNA concentration with dilution and path-length correction, inspect A260/A280 and A260/A230 purity ratios, and convert DNA ng/µL to nM when fragment length is known.
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Electrical & engineering
Bacterial Growth & Doubling Time Calculator — Population, Generations & Growth Rate
Solve exponential bacterial growth forward or recover doubling time from initial and final population. See generations, fold change and specific growth rate in the same time unit used for the entered duration.
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Electrical & engineering
Reynolds Number Calculator — Flow Regime, Dynamic & Kinematic Viscosity
Calculate Reynolds number from velocity, characteristic length and either kinematic viscosity or density plus dynamic viscosity. Classify common circular-pipe flow and see the alternate viscosity value.
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Electrical & engineering
Ideal Gas Law Calculator — Solve P, V, n or T with Unit Conversion
Enter any three ideal-gas variables and solve the fourth. Pressure, volume and temperature unit choices are converted to SI internally before PV=nRT is applied.
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Electrical & engineering
Air Density Calculator — Temperature, Pressure & Humidity
Calculate moist-air density from temperature, barometric pressure and relative humidity using dry-air and water-vapor partial pressures.
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Electrical & engineering
Mach Number Calculator — Speed, Temperature & Speed of Sound
Calculate Mach number from object speed and air temperature, or convert a target Mach number back to speed using the ideal-gas speed of sound.
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Electrical & engineering
Buoyancy Calculator — Archimedes Force, Apparent Weight & Float Check
Calculate buoyant force from displaced volume and fluid density, compare it with object weight and report net vertical force and a simple float/sink check.
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Electrical & engineering
Hydrostatic Pressure Calculator — Fluid Depth, Density & Absolute Pressure
Calculate gauge pressure from fluid density and depth, then optionally add atmospheric/surface pressure for absolute pressure.
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Electrical & engineering
Bernoulli Equation Calculator — Pressure, Velocity & Elevation Head
Compare two points in steady incompressible flow with Bernoulli’s equation and solve the missing downstream pressure or velocity from pressure, speed and elevation.
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Electrical & engineering
Darcy Friction Factor Calculator — Reynolds, Roughness & Colebrook
Calculate Darcy friction factor from Reynolds number and relative roughness using laminar 64/Re or the explicit Swamee-Jain turbulent approximation.
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Electrical & engineering
Prandtl Number Calculator — Viscosity, Heat Capacity & Thermal Conductivity
Calculate Prandtl number from dynamic viscosity, specific heat and thermal conductivity.
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Electrical & engineering
Orifice Flow Calculator — Flow Rate from Diameter, Pressure Drop & Cd
Calculate incompressible liquid flow through an orifice from diameter, pressure drop, fluid density and discharge coefficient.
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Electrical & engineering
qPCR Efficiency Calculator — Standard Curve, Slope, R² & Residuals
Calculate qPCR amplification efficiency from a slope or fit a complete Ct/Cq versus template standard curve. Get slope, intercept, R², efficiency, amplification factor and point-by-point residuals.
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Electrical & engineering
Nusselt Number Calculator — Convection, Conductivity & Heat Transfer
Calculate Nusselt number from convective heat-transfer coefficient, characteristic length and fluid conductivity, or recover h from Nu.
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Electrical & engineering
Darcy-Weisbach Calculator — Pipe Head Loss & Pressure Drop
Calculate pipe friction head loss and pressure drop from Darcy friction factor, length, diameter, velocity and density.
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Electrical & engineering
Hazen-Williams Calculator — Water Pipe Flow & Head Loss
Estimate water-pipe head loss from flow, diameter, length and Hazen-Williams C coefficient using the SI form.
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Electrical & engineering
Rayleigh Number Calculator — Natural Convection Regime
Calculate Rayleigh number from Grashof and Prandtl numbers or from fluid properties for buoyancy-driven convection.
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Electrical & engineering
Péclet Number Calculator — Advection vs Diffusion
Calculate thermal or mass Péclet number from velocity, characteristic length and diffusivity, with interpretation of transport dominance.
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Electrical & engineering
Biot Number Calculator — Lumped-Capacitance Validity Check
Calculate Biot number from convection coefficient, characteristic length and solid thermal conductivity, with a lumped-model guide.
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Electrical & engineering
Fourier Number Calculator — Thermal Diffusion Time Scale
Calculate Fourier number from thermal diffusivity, elapsed time and characteristic length, or solve the corresponding diffusion time.
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Electrical & engineering
Hydraulic Diameter Calculator — Non-Circular Ducts & Channels
Calculate hydraulic diameter from flow area and wetted perimeter, with direct rectangular-duct support.
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Electrical & engineering
Mass Flow Rate Calculator — Density, Velocity, Area & Volumetric Flow
Calculate mass flow from density and volumetric flow, or density, velocity and cross-sectional area; see equivalent volumetric flow.
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Electrical & engineering
Heat Transfer Coefficient Calculator — Convection h, Heat Rate & ΔT
Solve Q=hAΔT for convective heat-transfer coefficient, heat rate, area or temperature difference.
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Electrical & engineering
Thermal Diffusivity Calculator — α, k, Density & Specific Heat
Solve thermal diffusivity from conductivity, density and specific heat, or reverse-solve any one property. See volumetric heat capacity and practical mm²/s output.
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Electrical & engineering
LMTD Calculator — Counterflow & Parallel Heat Exchanger
Calculate log mean temperature difference for counterflow or parallel-flow heat exchangers, inspect both terminal temperature differences and optionally solve heat duty from UA.
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Electrical & engineering
Grashof Number Calculator — Natural Convection Gr
Calculate Grashof number from gravity, thermal expansion, temperature difference, characteristic length and kinematic viscosity; also report buoyancy-to-viscous force context.
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Electrical & engineering
Heat Exchanger NTU Calculator — Effectiveness, Duty & Outlets
Solve NTU-effectiveness for counterflow or parallel flow from hot/cold capacity rates, UA and inlet temperatures; report effectiveness, duty and outlet temperatures.
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Electrical & engineering
Minor Loss Calculator — K Factor, Head Loss & Pressure Drop
Calculate fitting and valve minor head loss and pressure drop from loss coefficient K, velocity and fluid density.
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Electrical & engineering
Thermal Resistance Calculator — Conduction R & Heat Rate
Calculate plane-wall conduction thermal resistance and heat rate from thickness, conductivity, area and temperature difference.
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Electrical & engineering
Fin Efficiency Calculator — Straight Rectangular Fin
Calculate adiabatic-tip straight-fin efficiency from convection coefficient, conductivity, thickness and length.
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Electrical & engineering
Heat Flux Calculator — Heat Rate, Area & Flux
Convert between heat rate, surface area and heat flux with a direct engineering qʺ=Q/A calculation.
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Electrical & engineering
Stefan-Boltzmann Calculator — Thermal Radiation Heat Flux
Calculate net radiative heat flux between a gray surface and large surroundings from emissivity and absolute temperatures.
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Electrical & engineering
Convection Heat Transfer Calculator — Newton Cooling Law
Calculate convection heat rate and heat flux from h, area, surface temperature and fluid temperature.
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Electrical & engineering
Critical Radius of Insulation Calculator — Cylinder & Sphere
Calculate the critical insulation radius for cylinders or spheres from insulation conductivity and external convection coefficient.
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Electrical & engineering
Thermal Stress Calculator — Restrained Expansion Stress
Calculate fully restrained uniaxial thermal stress from Young’s modulus, thermal expansion coefficient and temperature change.
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Electrical & engineering
Heat Exchanger Area Calculator — Q, U, LMTD & Correction Factor
Size preliminary heat-transfer area from duty, overall U-value, LMTD and correction factor, with design margin.
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Electrical & engineering
Pump Affinity Laws Calculator — RPM, Flow, Head & Power
Predict centrifugal-pump flow, head and power after a speed change using the affinity laws.
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Electrical & engineering
Compressor Power Calculator — Isentropic Gas Compression
Estimate ideal and shaft power plus discharge temperature for ideal-gas isentropic compression.
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Electrical & engineering
NPSH Available Calculator — Pump Suction Margin
Calculate pump net positive suction head available from absolute suction pressure, vapor pressure, density and suction velocity.
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Electrical & engineering
Venturi Flow Calculator — Differential Pressure to Flow
Calculate ideal incompressible Venturi flow and velocity from inlet/throat diameters, differential pressure, density and discharge coefficient.
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Electrical & engineering
Nozzle Velocity Calculator — Pressure Drop to Jet Speed
Estimate ideal or coefficient-adjusted liquid jet velocity and volumetric flow from pressure drop, density and nozzle diameter.
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Electrical & engineering
Drag Force Calculator — Fluid Dynamic Drag
Calculate aerodynamic or hydrodynamic drag from density, velocity, drag coefficient and reference area.
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Electrical & engineering
Terminal Velocity Calculator — Drag-Balanced Falling Speed
Calculate quadratic-drag terminal speed from mass, density, drag coefficient, area and displaced-fluid density effect.
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Electrical & engineering
Pipe Wall Shear Stress Calculator — Darcy Friction Factor
Calculate pipe wall shear stress and pressure gradient from Darcy friction factor, density, mean velocity and diameter.
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Electrical & engineering
Choked Flow Calculator — Gas Mass Flow & Critical Pressure
Calculate maximum ideal-gas mass flow through a nozzle or orifice and check whether the entered downstream pressure is low enough to choke the flow.
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Electrical & engineering
Isentropic Flow Calculator — Mach, Static Ratios & Area Ratio
Calculate ideal-gas static temperature, pressure and density ratios, velocity and nozzle area ratio from Mach number and stagnation conditions.
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Electrical & engineering
Normal Shock Calculator — Downstream Mach & Property Ratios
Calculate downstream Mach number, static pressure, density and temperature ratios across a normal shock for a perfect gas.
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Electrical & engineering
Oblique Shock Calculator — Shock Angle, Mach & Pressure Rise
Solve the weak attached oblique-shock angle from upstream Mach and flow deflection, then calculate downstream Mach and normal-shock property ratios.
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Electrical & engineering
Fanno Flow Calculator — Frictional Compressible Duct Ratios
Calculate Fanno-line property ratios and the remaining friction parameter to sonic choking from Mach number and specific-heat ratio.
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Electrical & engineering
Rayleigh Flow Calculator — Heat-Addition Compressible Ratios
Calculate Rayleigh-line static and stagnation property ratios relative to sonic conditions for a perfect gas.
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Electrical & engineering
Pipe Equivalent Length Calculator — K-Factor to Added Pipe Length
Convert fitting loss coefficient to equivalent straight-pipe length and combine it with the installed straight run for pressure-loss workflows.
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Electrical & engineering
Composite Wall Thermal Resistance Calculator — Layers, U-Value & Heat Loss
Calculate series resistance of up to three plane-wall layers, overall U-value and steady heat flow including optional inside and outside film resistances.
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Electrical & engineering
Radiation View Factor Calculator — Facing Surface Approximation
Estimate the geometric view factor between two small directly facing surfaces and net black/gray radiant exchange for first-pass thermal checks.
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Electrical & engineering
Pump System Curve Calculator — Operating Point, Static Head & Friction Curve
Build a pump-system head curve and solve the pump/system intersection to estimate operating flow, operating head and friction-head share. The same canonical owner covers pump operating point, system resistance curve and centrifugal pump curve intersection intent without creating duplicate calculators.
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Electrical & engineering
Psychrometric Calculator — Dew Point, Wet Bulb, Humidity & Enthalpy
Resolve a moist-air state from dry-bulb temperature plus relative humidity, dew point or wet-bulb temperature. Calculate humidity ratio, enthalpy, specific volume, density, vapour pressure and condensation margin with altitude-aware pressure.
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Electrical & engineering
Air Changes per Hour Calculator — ACH, CFM & Room Volume
Calculate ACH from room dimensions and airflow, plus the CFM and m³/h required for a target air-change rate.
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Electrical & engineering
Duct Size Calculator — CFM, Velocity, Round & Rectangular
Size round and rectangular duct cross-sections from airflow and target velocity, with actual area and equivalent round diameter.
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Electrical & engineering
Duct Velocity Calculator — CFM, FPM & Air Speed
Calculate air velocity from CFM and round or rectangular duct dimensions, with FPM and m/s outputs.
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Electrical & engineering
HVAC Sensible Heat Calculator — CFM, ΔT & BTU/h
Calculate sensible air-side heat transfer from airflow and temperature difference, with BTU/h, kW and tons outputs.
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Electrical & engineering
Chilled Water Flow Calculator — GPM, kW, Tons & ΔT
Calculate chilled-water flow from cooling load and temperature difference, or show the carried load for an entered GPM.
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Electrical & engineering
Refrigeration COP Calculator — Cooling Capacity, Power & Carnot Limit
Calculate refrigeration COP from cooling capacity and input power, then compare with the Carnot COP from evaporating and condensing temperatures.
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Electrical & engineering
HVAC Superheat Calculator — Suction vs Saturation Temperature
Calculate evaporator superheat from measured suction-line temperature and evaporating saturation temperature in °F or °C.
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Electrical & engineering
HVAC Subcooling Calculator — Condensing vs Liquid Temperature
Calculate condenser subcooling from condensing saturation temperature and measured liquid-line temperature in °F or °C.
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Electrical & engineering
Fan Power Calculator — Airflow, Static Pressure & Efficiency
Calculate ideal air power and estimated shaft/input power from airflow, pressure rise and fan efficiency.
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Electrical & engineering
EER to COP Converter — HVAC Efficiency Conversion
Convert EER in BTU/Wh to COP and back, and estimate input power from cooling capacity and efficiency.
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Electrical & engineering
Mixed Air Temperature Calculator — HVAC Mixing & Outside Air %
Mix outside and return air by airflow, calculate mixed-air temperature and outside-air fraction, or reverse-solve the outside-air percentage needed for a target mixed-air temperature.
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Electrical & engineering
Humidification Load Calculator — Airflow, Humidity Ratio & kg/h
Size first-pass humidification moisture capacity from airflow and entering/target humidity ratio, with kg/h, lb/h and water L/h outputs.
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Electrical & engineering
Duct Friction Rate Calculator — Pressure Loss, Reynolds & Equal-Friction Check
Calculate straight round-duct friction rate with Darcy-Weisbach, Reynolds number and Swamee-Jain friction factor, plus total run loss and common HVAC units.
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Electrical & engineering
Heating Load Calculator — U-Value, Area, Infiltration & Heater Size
Estimate design heating load from envelope UA loss plus infiltration, with watts, BTU/h, kW and a configurable sizing margin.
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Electrical & engineering
Radiator Size Calculator — Room Heat Output, BTU/h & ΔT Correction
Convert a room design load into required radiator output and correct a catalog ΔT50 rating to another mean-water-to-room temperature difference.
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Electrical & engineering
Boiler Efficiency Calculator — Fuel Input, Useful Heat & Fuel Cost
Calculate direct boiler efficiency, heat loss, useful output and fuel required from fuel rate, heating value and delivered thermal output.
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Electrical & engineering
Heating Degree Days Calculator — HDD, CDD & Base Temperature
Calculate heating and cooling degree days from mean outdoor temperature, balance-point temperature and period length in °C-day and °F-day.
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Electrical & engineering
Steam Quality Calculator — Dryness Fraction, Enthalpy & Wet Steam
Calculate wet-steam quality from mixture enthalpy and saturated liquid/vapor enthalpies, or mixture enthalpy from entered dryness fraction.
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Electrical & engineering
Heat Pump COP Calculator — Heating Output, Power & Carnot COP
Calculate heating COP from delivered heat and electrical input, with ideal Carnot heating COP and percentage of Carnot.
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Electrical & engineering
Furnace Size Calculator — Heating Load, Efficiency & Input BTU/h
Convert a design heating load into required furnace input capacity from AFUE/thermal efficiency and sizing margin.
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Electrical & engineering
Ventilation Heat Loss Calculator — Airflow, ΔT & Heat Recovery
Calculate sensible ventilation heating load from airflow and temperature difference, including heat-recovery effectiveness.
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Electrical & engineering
Pipe Heat Loss Calculator — U-Value, Diameter, Length & Temperature
Estimate steady pipe heat loss from overall U-value, outside diameter, length and fluid-to-ambient temperature difference.
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Electrical & engineering
Cooling Tower Range & Approach Calculator — Effectiveness and Heat Rejection
Calculate cooling-tower range, approach, effectiveness and water-side heat rejection from hot/cold water and wet-bulb temperatures plus flow.
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Electrical & engineering
Sensible Heat Ratio Calculator — SHR, Sensible & Latent Load
Solve HVAC sensible heat ratio from sensible and latent or total capacity, and reverse-solve either load from SHR. Shows the complete sensible/latent split in kW and BTU/h.
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Electrical & engineering
Cooling Coil Condensate Calculator — Humidity Ratio, Water Removal & Latent Load
Estimate cooling-coil condensate from dry-air flow and entering/leaving humidity ratio, with kg/h, L/h, US gal/h and equivalent latent cooling load.
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Electrical & engineering
Grille Free Area Calculator — CFM, Face Velocity & Required Size
Calculate HVAC grille/register net free area and face velocity, or reverse-size required gross face area from airflow, target velocity and free-area ratio.
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Electrical & engineering
Fan Affinity Laws Calculator — RPM, CFM, Pressure, Power & VFD Savings
Predict fan airflow, pressure and power after an RPM change, or reverse-solve RPM from target airflow. Includes percent changes, ideal energy savings and optional annual electricity-cost impact.
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Electrical & engineering
Hydronic Expansion Tank Calculator — Water Expansion, Acceptance & Tank Volume
Estimate closed-loop hydronic expansion-tank acceptance and nominal tank volume from system water volume, cold/hot density, fill pressure and relief pressure.
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Electrical & engineering
Cooling Coil Bypass Factor Calculator — BF, Contact Factor & ADP
Calculate cooling-coil bypass factor from entering, leaving and apparatus-dew-point temperatures, plus contact factor and reverse leaving-air temperature.
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Electrical & engineering
ERV Effectiveness Calculator — Sensible, Latent & Recovered Load
Estimate sensible and latent energy-recovery effectiveness, supply leaving conditions and recovered sensible/latent load from airflow and indoor/outdoor states.
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Electrical & engineering
Ventilation Latent Load Calculator — Outdoor Air Moisture & Tons
Calculate latent HVAC load from outdoor-air flow and indoor/outdoor humidity ratio, with moisture removal in kg/h and latent capacity in kW, BTU/h and tons.
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Electrical & engineering
Filter Face Velocity Calculator — CFM, Area & Required Filter Size
Calculate HVAC filter face velocity from airflow and filter dimensions, or reverse-size required gross filter area from a target velocity.
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Electrical & engineering
HVAC Air-Side Pressure Budget Calculator — ESP, Components & Fan Margin
Sum duct, fitting, filter, coil, grille and accessory pressure losses, compare them with available fan static pressure and report remaining margin.
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Electrical & engineering
Glycol Expansion Calculator — Closed-Loop Expansion & Tank Acceptance
Estimate glycol-loop thermal expansion and ideal diaphragm-tank volume from system volume, cold/hot fluid density, fill pressure, relief pressure and design margin.
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Electrical & engineering
Duct Leakage Calculator — CFM25, Leakage Class & Percent Airflow
Calculate duct leakage from leakage coefficient/class, duct surface area and test pressure, then compare leakage with design airflow.
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Electrical & engineering
Cooling Tower Cycles of Concentration Calculator — Blowdown & Makeup
Calculate cooling-tower cycles of concentration from makeup and circulating-water concentration, then estimate evaporation, blowdown and makeup flow.
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Electrical & engineering
Boiler Blowdown Calculator — Blowdown Rate, Makeup & Heat Loss
Estimate continuous boiler blowdown from feedwater and boiler-water TDS limits, plus makeup requirement and approximate sensible heat carried by blowdown.
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Electrical & engineering
Condensate Return Calculator — Return %, Makeup Water & Heat Recovery
Calculate steam-system condensate return percentage, makeup-water demand and approximate sensible heat recovered from hot condensate versus makeup water.
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Electrical & engineering
Hydronic Pipe Sizing Calculator — Flow, Velocity, Head Loss & Pump Head
Size a hydronic water pipe from flow and inside diameter, calculate velocity, Reynolds number, Darcy friction factor, straight-plus-equivalent-length head loss and pump pressure drop.
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Electrical & engineering
Cooling Coil Face Velocity Calculator — Airflow, Face Area & Carryover Check
Calculate cooling-coil face velocity from airflow and coil dimensions, reverse-size required face area from a target velocity and flag entered carryover-limit exceedance.
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Electrical & engineering
Cooling Tower Water Balance Calculator — Evaporation, Drift, Blowdown & Makeup
Calculate cooling-tower range, heat rejection, evaporation, drift, blowdown, makeup water and annual water use from circulation, temperatures and cycles of concentration.
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Electrical & engineering
Flash Steam Calculator — Condensate Letdown, Flash % & Recovery
Estimate flash-steam fraction when saturated condensate drops to a lower pressure, plus flash flow, remaining condensate and recoverable flash energy using an explicit enthalpy-property approximation.
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Electrical & engineering
Heat Recovery Payback Calculator — Annual Savings, CO₂ & Simple Payback
Convert recoverable heat, utilization, operating hours, displaced-system efficiency, energy tariff and project cost into annual useful heat, purchased-energy savings, money savings, CO₂ reduction and simple payback.
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Electrical & engineering
Steam Trap Sizing Calculator — Condensate Load, Safety Factor & Differential Pressure
Estimate design trap condensate capacity from running load and startup safety factor, and expose available differential pressure after return backpressure.
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Electrical & engineering
Chiller kW per Ton Calculator — Efficiency, COP & Annual Energy Cost
Calculate chiller kW/ton, COP, EER-equivalent, annual electricity use and cost from measured electrical input and cooling output.
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Electrical & engineering
Pump Total Dynamic Head Calculator — Static, Pressure, Friction & Velocity Head
Calculate pump TDH by combining elevation, vessel-pressure difference, suction/discharge friction and velocity-head change with fluid specific gravity.
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Electrical & engineering
Steam Pipe Sizing Calculator — Mass Flow, Specific Volume, Velocity & Diameter
Size a steam line from mass flow, entered steam specific volume and target velocity, or check velocity for an entered inside diameter.
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Electrical & engineering
Boiler Steam Output Calculator — Fuel Input, Efficiency & Steam Generation
Estimate useful boiler duty and steam generation from fuel input, boiler efficiency, feedwater enthalpy and steam enthalpy.
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Electrical & engineering
Heat Exchanger Duty Calculator — Flow, Cp, ΔT & Energy Balance
Calculate hot- or cold-side heat duty from mass flow, specific heat and temperature change, then compare two entered sides with an energy-balance mismatch.
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Electrical & engineering
Condenser Water Flow Calculator — Heat Rejection, Range & GPM
Calculate condenser-water flow from heat rejection and water temperature range, with SI and US flow outputs.
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Electrical & engineering
Air Compressor CFM Calculator — Receiver Pump-Up Free Air Delivery
Estimate compressor free-air delivery from receiver volume, pressure rise, atmospheric pressure and measured pump-up time.
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Electrical & engineering
Compressed Air Leak Calculator — Orifice Flow, Annual Air Loss & Energy Cost
Estimate sonic-orifice compressed-air leakage, annual free-air loss and electricity cost from hole diameter, upstream pressure, temperature, compressor specific power and operating hours.
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Electrical & engineering
Steam Velocity Calculator — Mass Flow, Specific Volume & Pipe Velocity
Calculate volumetric steam flow and line velocity from mass flow, specific volume and actual pipe inside diameter, with target-velocity comparison.
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Electrical & engineering
Compressed Air Receiver Sizing Calculator — CFM, Pressure Band & Hold Time
Size a compressed-air receiver from peak demand, compressor supply, usable pressure band and required hold time. Returns required storage in litres, cubic metres, cubic feet and US gallons, plus practical standard-size guidance.
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Electrical & engineering
Pump Wire-to-Water Efficiency Calculator — Hydraulic Power, Pump & Motor Losses
Calculate hydraulic output, wire-to-water efficiency, estimated pump efficiency after motor losses, wasted electrical power and annual loss cost from measured flow, head and electrical input.
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Electrical & engineering
Steam Cost Calculator — Fuel, Water, Chemicals, Power & Condensate Credit
Estimate true steam production cost from boiler enthalpy rise and efficiency, fuel energy price, makeup-water/chemical cost, auxiliary electricity and condensate-return credit. Returns cost per tonne and per 1,000 lb plus annual spend.
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Electrical & engineering
Compressor Specific Power Calculator — kW/100 CFM, kW/(m³/min) & Cost
Benchmark an air compressor from measured package power and free-air delivery. Returns kW per m³/min, kW per 100 CFM, specific energy, annual electricity use and annual cost.
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Electrical & engineering
Condensate Pipe Sizing Calculator — Flow, Velocity & Diameter
Size a liquid condensate return line from mass flow, density and target velocity. Returns required internal diameter, volumetric flow and practical velocity checks in SI and US units.
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Electrical & engineering
Chiller IPLV / NPLV Calculator — Weighted Part-Load Efficiency
Calculate a transparent weighted part-load chiller efficiency from 100%, 75%, 50% and 25% load-point kW/ton values using AHRI-style IPLV weighting, with equivalent COP and annualized comparison outputs.
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Electrical & engineering
Boiler Fuel Comparison Calculator — Useful Heat Cost & Annual Savings
Compare two boiler fuels on a common useful-heat basis using fuel energy price and boiler efficiency. Returns useful heat cost, annual fuel input, annual spend, savings and break-even fuel price.
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Electrical & engineering
Compressed Air Pressure Drop Calculator — Darcy Friction, Velocity & Downstream Pressure
Estimate compressed-air pipe friction with pressure-corrected actual flow, Reynolds number and Darcy-Weisbach loss. Returns velocity, Reynolds number, friction factor, pressure drop and downstream pressure.
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Electrical & engineering
Chiller Plant Efficiency Calculator — Total Plant kW/Ton, COP & Cost
Benchmark whole chilled-water plant efficiency by combining chiller, chilled-water pump, condenser-water pump and cooling-tower fan power against measured cooling load.
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Electrical & engineering
Pump Specific Speed Calculator — US Ns, Metric nq & Impeller Class
Calculate centrifugal-pump specific speed from BEP speed, flow and head per stage. Returns US Ns, metric nq and a screening impeller-flow classification.
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Electrical & engineering
Steam Accumulator Sizing Calculator — Peak Load Storage & Vessel Volume
Estimate steam accumulator storage for a peak-load shortfall from demand, boiler supply, event duration and usable stored-energy density. Returns required stored energy, equivalent steam mass and vessel volume.
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Electrical & engineering
Boiler Blowdown Heat Recovery Calculator — Recoverable kW & Annual Savings
Estimate recoverable heat from continuous boiler blowdown using mass flow, hot blowdown temperature, return temperature and recovery effectiveness. Returns thermal kW, annual MWh and annual value.
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Electrical & engineering
Compressed Air Moisture Calculator — Condensate Load & Dryer Duty
Estimate water entering with compressor intake air and condensate removed after cooling from ambient temperature/RH, free-air delivery, pressure and aftercooler temperature. Returns inlet moisture, retained moisture and condensate per hour/day.
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Electrical & engineering
Cooling Tower Fan Specific Power Calculator — kW per Flow & Heat Rejection
Benchmark cooling-tower fan demand against circulating-water flow and rejected heat. Returns kW per 1,000 gpm, W per m³/h, fan kW per rejected MW and annual energy.
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Electrical & engineering
Chiller Lift Calculator — Temperature Lift, Pressure Lift & Lift Ratio
Calculate evaporator-to-condenser temperature lift and optional pressure lift for chiller diagnostics, including Kelvin lift ratio and approach context.
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Electrical & engineering
Compressed Air Heat Recovery Calculator — Recoverable kW, MWh & Savings
Estimate useful heat recoverable from compressor package input power using recoverable fraction, operating hours, utilization and heat value.
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Electrical & engineering
Boiler Excess Air from O₂ Calculator — Flue-Gas O₂ & Air Ratio
Estimate excess combustion air from dry flue-gas oxygen using the common 21/(21−O₂) air-ratio approximation. Returns excess-air percent, air ratio and sensitivity.
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Electrical & engineering
Steam Header Diversity Calculator — Coincident Peak & Diversity Factor
Size a steam-header screening load from connected branch peaks and a diversity/coincidence factor. Returns connected load, diversified peak, spare capacity and utilization.
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Electrical & engineering
Chiller Condenser Approach Calculator — Saturation vs Leaving Water
Calculate condenser approach from refrigerant condensing saturation temperature and leaving condenser-water temperature, with entering-water range context.
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Electrical & engineering
Chiller Evaporator Approach Calculator — Leaving Water vs Saturation
Calculate evaporator approach from leaving chilled-water temperature and refrigerant evaporating saturation temperature, with water-side range.
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Electrical & engineering
Boiler Evaporation Ratio Calculator — Steam-to-Fuel Ratio & Specific Steam
Calculate actual evaporation ratio from steam production and fuel use, then compare against a target and estimate fuel saving at the same steam output.
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Electrical & engineering
Boiler Combustion Air Calculator — Stoichiometric Air, Excess Air & Fan Flow
Estimate actual combustion-air mass and standard volumetric flow from fuel flow, stoichiometric air requirement and excess-air percentage.
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Electrical & engineering
Steam Turbine Power Calculator — Enthalpy Drop, Efficiency & Generator Output
Calculate ideal fluid power, shaft power and generator output from steam mass flow, inlet/outlet enthalpy, turbine efficiency and generator efficiency.
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Electrical & engineering
Boiler Stack Loss Calculator — Siegert Loss, Excess Air & Combustion Efficiency
Estimate dry sensible stack loss from flue temperature, combustion-air temperature and dry O₂, while also showing excess air and indicated combustion efficiency.
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Electrical & engineering
Boiler Economizer Duty Calculator — Feedwater Heat Recovery & Fuel Savings
Calculate feedwater preheat duty, annual recovered heat and equivalent fuel saving from water flow, inlet/outlet temperature, boiler efficiency and fuel heating value.
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Electrical & engineering
Steam Turbine Heat Rate Calculator — Heat Rate, Efficiency & Steam Rate
Benchmark turbine-generator performance from thermal input, electrical output and steam flow. Returns heat rate, thermal efficiency and specific steam consumption.
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Electrical & engineering
Condenser Vacuum Calculator — Absolute Pressure, Vacuum & Vacuum Percent
Convert barometric and condenser absolute pressure into vacuum pressure, vacuum percentage and equivalent kPa/bar values for steam-plant diagnostics.
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Electrical & engineering
Chiller Fouling Index Calculator — Approach Rise & Efficiency Penalty
Trend condenser or evaporator approach against a clean baseline and pair the approach rise with measured kW/ton change to quantify a practical fouling-performance signal.
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Electrical & engineering
Cooling Tower Fan Affinity Calculator — VFD Speed, Airflow, Pressure & Power
Estimate cooling-tower fan airflow, pressure and power at a new speed using affinity laws, with annual energy difference for VFD screening.
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Electrical & engineering
Compressed Air Artificial Demand Calculator — Pressure Reduction Energy & Cost
Estimate avoidable compressed-air demand and energy caused by operating above the required pressure, using measured flow, pressure sensitivity, specific power and annual hours.
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Electrical & engineering
Steam Pressure Reduction Energy Calculator — PRV Enthalpy Drop Opportunity
Screen the thermal-power scale associated with a steam pressure-reduction station using steam flow and validated upstream/downstream enthalpy values.
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Electrical & engineering
Boiler Load Factor Calculator — Average Load, Capacity Utilization & Equivalent Full Load Hours
Calculate boiler average load factor, capacity utilization, equivalent full-load hours and unused capacity from rated output, production and operating hours.
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Electrical & engineering
Condensate Energy Recovery Calculator — Return Heat, Fuel Value & Annual Savings
Estimate sensible heat returned with hot condensate relative to makeup water, then convert it into boiler-fuel equivalent and annual monetary value.
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Electrical & engineering
Deaerator Steam Consumption Calculator — Heat Balance & Steam Demand
Estimate deaerator heating-steam demand from feedwater flow and inlet/outlet enthalpy using a transparent steady-state energy balance.
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Electrical & engineering
Boiler Feed Pump Power Calculator — Differential Head, Hydraulic & Motor Power
Calculate boiler-feed-pump differential head, hydraulic power, shaft power and electrical input from flow, suction/discharge pressure, elevation and efficiencies.
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Electrical & engineering
Steam Nozzle Flow Calculator — Choked Mass Flow & Critical Pressure
Calculate ideal-gas steam/nozzle choked mass flow, critical pressure ratio and throat velocity scale from upstream absolute pressure, temperature, throat area, Cd, k and gas constant.
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Electrical & engineering
Steam Vent Capacity Calculator — Vent Mass Flow & Equivalent Diameter
Estimate required vent area and equivalent diameter for a target steam/gas mass flow using the same auditable choked-flow relation with user-supplied discharge coefficient.
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Electrical & engineering
Cooling Tower Evaporation Loss Calculator — Heat Rejection & Water Loss
Estimate evaporation from circulation/range or measured heat rejection, and show annual water loss with an explicit latent-heat assumption.
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Electrical & engineering
Cooling Tower Drift Loss Calculator — Drift Rate, Annual Water & Solids Carryover
Calculate drift water loss from circulation and drift percentage, with annual volume and dissolved-solids carryover from cycles/TDS input.
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Electrical & engineering
Chiller Delta-T Calculator — Cooling Load, Flow & Low-ΔT Diagnosis
Solve chilled-water ΔT, cooling load or design flow from any consistent pair and report tons plus a low-ΔT comparison against a target.
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Electrical & engineering
Compressed Air Storage Capacity Calculator — Usable Air, Ride-Through & Receiver Volume
Calculate usable free-air storage between two receiver pressures, ride-through time for a net demand, or required receiver volume.
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Electrical & engineering
Compressor Unload Savings Calculator — Loaded/Unloaded Energy & Annual Cost
Estimate annual compressor energy and savings from measured loaded/unloaded power and duty cycle, then compare with an improved unload/control case.
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Electrical & engineering
Steam Line Warm-Up Calculator — Pipe Heating Load, Condensate & Warm-Up Rate
Estimate sensible energy and equivalent steam condensate required to warm a steel steam line from ambient to operating temperature over a chosen warm-up time.
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Electrical & engineering
Deaerator Storage Sizing Calculator — Hold-Up Time, Working Volume & Tank Capacity
Size deaerator storage from boiler-feedwater demand, required hold-up time, usable tank fraction and design margin. Returns working water volume, minimum gross vessel volume and stored mass.
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Electrical & engineering
Boiler Feedwater Control Valve Cv Calculator — Required Cv, Margin & Pressure Drop
Estimate liquid control-valve Cv for boiler feedwater from flow, specific gravity and available valve pressure drop, then apply a selectable design margin and report pressure-drop share.
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Electrical & engineering
Condensate Receiver Sizing Calculator — Return Flow, Hold-Up & Pump Cycling Volume
Size a vented condensate receiver from return mass flow, liquid density, desired hold-up time, usable level fraction and margin. Returns liquid flow, working volume, gross receiver volume and pump-cycle storage.
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Electrical & engineering
Air Compressor Sequencing Calculator — Base/Trim Split, Loading & kW
Screen a base-plus-trim compressor sequence from plant demand, fixed-speed base capacity/power and VSD trim capacity/power. Reports base machines required, trim flow, trim loading, estimated system kW and specific power.
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Electrical & engineering
Steam Separator Sizing Calculator — Velocity, Area & Diameter
Screen a steam separator or line bore from steam mass flow, specific volume and target velocity. Returns volumetric flow, required free area and equivalent diameter.
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Electrical & engineering
Compressed Air Demand Profile Calculator — Weighted CFM, Peak & Load Factor
Combine four demand periods into time-weighted average flow, peak flow, daily air volume and load factor for compressor planning.
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Electrical & engineering
Compressor Sequencing Savings Calculator — Annual kWh, Cost & Payback
Compare baseline and optimized compressor package kW at the same demand to estimate annual kWh savings, cost savings, percent reduction and simple payback.
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Electrical & engineering
Deaerator Level Band Calculator — Usable Volume & Ride-Through Time
Calculate usable deaerator storage between low/high level fractions and convert that inventory into ride-through time at a stated net draw.
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Electrical & engineering
Condensate Receiver Level Band Calculator — Pump Cycle Volume & Runtime
Calculate receiver volume between pump start/stop levels, fill time, pump-out time and approximate cycles per hour from return and pump rates.
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Electrical & engineering
Boiler Turndown Calculator — Minimum Stable Load & Cycling Gap
Calculate minimum stable firing output from rated capacity and turndown ratio, then compare a site minimum load to estimate excess capacity and cycling risk.
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Electrical & engineering
Condensate Pump Sizing Calculator — Design Flow, Head & Motor kW
Size a condensate return pump from return flow, pickup factor, static head, friction/pressure allowance, density and efficiency. Returns design flow, TDH and input power.
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Electrical & engineering
Cooling Tower Blowdown Savings Calculator — COC Water Savings
Compare cooling-tower blowdown at current and target cycles of concentration from evaporation and drift, then estimate annual water and cost savings.
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Electrical & engineering
Steam Leak Cost Calculator — Annual Steam, Energy & Cost Loss
Convert a measured or estimated steam leak rate into annual lost steam, thermal energy and cost using operating hours, steam enthalpy basis and steam cost.
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Electrical & engineering
Boiler Standby Loss Calculator — Idle Energy & Annual Cost
Estimate annual standby energy and fuel-cost exposure from boiler rated input, measured or assumed standby-loss percentage, idle hours and fuel-energy cost.
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Electrical & engineering
Steam Trap Survey Loss Calculator — Failed Traps, Steam, Energy & Annual Cost
Turn a steam-trap survey into a fleet-level loss estimate. Model failed-open and leaking traps separately, apply a measured or engineering leak rate, then calculate failed trap count, steam loss, thermal loss, annual tonnes, annual cost and repair-payback screening.
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Electrical & engineering
Compressed Air Pipe Velocity Calculator — SCFM, Pressure & Bore
Convert free-air flow to approximate line-condition flow and velocity using absolute-pressure ratio, pipe inside diameter and temperature ratio.
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Electrical & engineering
Cooling Tower Heat Rejection Calculator — Water Flow, Range & Tons
Calculate rejected heat from circulating-water flow and tower range, with kW, refrigeration-ton equivalent and water mass-flow audit outputs.
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Electrical & engineering
Steam Accumulator Discharge Duration Calculator — Usable Energy & Peak Support
Estimate how long stored usable thermal energy can support a steam-demand deficit, with reserve-aware usable energy and peak-deficit outputs.
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Electrical & engineering
Compressed Air Leakage Percentage Calculator — Load/Unload Test & Cost
Estimate leakage fraction from compressor load/unload timing during a no-production test, then convert leakage flow into annual energy and cost using specific power.
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Electrical & engineering
Boiler Makeup Water Calculator — Steam, Condensate Return & Blowdown
Calculate makeup-water demand from steam production, condensate return and blowdown, with return ratio and annual water requirement.
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Electrical & engineering
Chiller Heat Rejection Calculator — Cooling Load + Compressor Power
Calculate condenser heat rejection as evaporator cooling load plus compressor input, with kW and refrigeration-ton outputs and rejection ratio.
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Electrical & engineering
Steam Distribution Efficiency Calculator — Generated vs Delivered Steam
Compare generated steam with useful delivered/process steam to quantify distribution efficiency, losses, annual lost tonnes and cost.
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Electrical & engineering
Compressed Air System Efficiency Calculator — Useful Air Power vs Electrical kW
Estimate simple pressure-flow power at point of use from free-air flow and pressure, compare it with measured electrical input and report a transparent system-efficiency indicator.
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Electrical & engineering
Boiler Steam-to-Fuel Ratio Calculator — kg Steam/kg Fuel & Specific Fuel
Calculate steam-to-fuel ratio, specific fuel consumption and optional benchmark gap from measured steam and fuel mass flows.
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Electrical & engineering
Compressed Air Pressure Reduction Savings Calculator — kW, kWh & Payback
Screen compressor energy savings from a proposed system-pressure reduction using measured package power and an entered percent-power reduction per pressure step.
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Electrical & engineering
Pump Throttling Loss Calculator — Valve Head, Wasted kW & VFD Opportunity
Quantify hydraulic power dissipated across a throttling valve from flow and excess head, estimate electrical input associated with that loss, and annualize the energy-cost opportunity.
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Electrical & engineering
Steam Pipe Insulation Savings Calculator — Heat Loss, Fuel & Annual Cost
Compare bare and insulated steam-pipe heat-loss rates per metre, multiply by exposed length and operating hours, then convert avoided thermal loss into fuel and annual cost savings.
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Electrical & engineering
Boiler Oxygen Trim Savings Calculator — Excess O₂, Fuel Reduction & Payback
Screen boiler oxygen-trim economics from measured fuel use, proposed fractional fuel reduction, operating hours and fuel price, with annual fuel, cost and simple-payback outputs.
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Electrical & engineering
Chiller Setpoint Savings Calculator — Leaving Water Reset & Annual kWh
Estimate annual chiller savings from a chilled-water setpoint reset using measured baseline kW and an entered percent-power improvement per degree of reset.
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Electrical & engineering
Condensate Recovery Energy Savings Calculator — Heat, Water & Fuel
Estimate recoverable sensible heat in returned condensate relative to makeup water, then convert it to boiler-fuel equivalent and annual energy value.
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Electrical & engineering
Compressed Air Receiver Fill Time Calculator — Volume, Pressure Band & Compressor Flow
Estimate receiver pressurization time from vessel volume, starting and final absolute pressures and compressor free-air delivery using an isothermal ideal-gas balance.
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Electrical & engineering
Cooling Tower Fan Power Savings Calculator — Speed, Fan Laws & Annual kWh
Estimate cooling-tower fan power at reduced speed using the cube law, then calculate kW, annual kWh and cost savings against measured baseline power.
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Electrical & engineering
Pump Bypass Recirculation Loss Calculator — Wasted Flow, kW & Cost
Quantify energy carried by unnecessary bypass or recirculation flow using measured bypass flow, pump head and efficiencies, then annualize wasted electrical energy and cost.
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Electrical & engineering
Boiler Feedwater Heating Duty Calculator — Flow, Temperature Rise & Steam Equivalent
Calculate feedwater sensible-heating duty from mass flow and temperature rise, with kW, annual thermal energy and an approximate steam-equivalent heating requirement.
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Electrical & engineering
Compressed Air Dryer Purge Loss Calculator — CFM, kW & Annual Cost
Quantify desiccant-dryer purge air from inlet flow and purge percentage, then convert lost compressed air into compressor power, annual energy and cost.
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Electrical & engineering
Condensate Contamination Loss Calculator — Rejected Return, Heat & Water Cost
Estimate the thermal and water penalty when contaminated condensate must be rejected instead of returned to the boiler house.
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Electrical & engineering
Chiller Condenser Water Reset Savings Calculator — Lift, kW & Annual Energy
Screen chiller compressor savings from lowering entering condenser-water temperature using measured baseline power and a site-validated percent-per-degree response.
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Electrical & engineering
Steam Vent Loss Calculator — Steam Mass, Heat & Annual Cost
Convert measured or estimated steam venting rate into thermal loss, annual steam mass and cost using entered steam enthalpy and operating duration.
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Electrical & engineering
Cooling Tower Water Cost Calculator — Makeup, Blowdown & Annual Spend
Annualize cooling-tower makeup and blowdown volumes and combine water, sewer and treatment rates into an operating-cost baseline.
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Electrical & engineering
Boiler Conductivity & Blowdown Calculator — Cycles, Flow, Heat & Water Cost
Set a continuous boiler blowdown rate from feedwater and boiler-water conductivity, then quantify cycles of concentration, feedwater demand, heat carried above makeup temperature and annual treated-water value.
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Electrical & engineering
Pump Minimum Flow Recirculation Calculator — Bypass Flow, kW & Heat
Calculate required bypass flow when process demand falls below a pump minimum-flow limit and estimate recirculation hydraulic power.
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Electrical & engineering
Compressor Unloaded Running Cost Calculator — Idle kW, kWh & Savings
Calculate energy and cost consumed while a compressor runs unloaded, plus the opportunity from reducing unloaded hours or improving sequencing.
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Electrical & engineering
Steam Header Pressure Drop Calculator — Velocity, Friction & Outlet Pressure
Estimate preliminary steam-header friction pressure drop from mass flow, density, pipe diameter, length and Darcy friction factor, with velocity and outlet-pressure checks.
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Electrical & engineering
Cooling Tower Wet-Bulb Margin Calculator — Approach, Design Margin & Effectiveness
Compare measured cooling-tower leaving-water temperature with current and design wet-bulb conditions to expose approach, weather margin and thermal effectiveness.
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Electrical & engineering
Pump Impeller Trim Calculator — Flow, Head & Power Affinity
Estimate a preliminary trimmed-impeller operating point from diameter ratio using pump affinity relationships for flow, head and power.
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Electrical & engineering
Compressed Air Pressure Dew Point Converter — PDP to Atmospheric Dew Point
Convert a pressure dew point at one absolute pressure to the equivalent dew point after expansion or compression using water-vapor partial-pressure scaling.
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Electrical & engineering
Cooling Tower L/G Ratio Calculator — Water-to-Dry-Air Mass Ratio
Calculate cooling-tower liquid-to-gas mass ratio from circulating-water and dry-air volumetric flow with entered densities.
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Electrical & engineering
Flash Steam Percentage Calculator — Condensate Letdown & Flash Flow
Calculate flash-steam fraction and mass flow from high-pressure condensate liquid enthalpy and low-pressure saturated liquid/latent enthalpy.
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Electrical & engineering
Compressed Air Cost per CFM Calculator — kWh, Annual Cost & Unit Air Cost
Convert compressor specific power, airflow, operating hours and electricity tariff into annual energy, annual spend and cost per CFM-hour.
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Electrical & engineering
Pump Energy Cost Calculator — kWh, Annual Spend & Cost per Volume
Calculate pump electrical input from flow, head, density and overall efficiency, then annualize energy cost and cost per pumped volume.
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Electrical & engineering
Chiller Annual Energy Cost Calculator — Tons, kW/ton, kWh & Spend
Annualize chiller compressor energy and electricity cost from refrigeration tons, measured or rated kW/ton, operating hours and tariff.
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Electrical & engineering
Cooling Tower Chemical Dose Cost Calculator — ppm, Feed Rate & Annual Spend
Convert a target active chemical dose and makeup-water flow into product feed rate, annual product consumption and treatment cost.
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Electrical & engineering
Pump Impeller Tip Speed Calculator — Diameter, RPM & Peripheral Velocity
Calculate impeller peripheral tip speed from rotational speed and diameter, with revolutions per second and circumference as audit outputs.
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Electrical & engineering
Condensate Cooling Duty Calculator — Sensible Heat, kW & Annual Energy
Calculate sensible cooling duty when hot condensate is cooled to a target temperature, plus annual recoverable or rejected thermal energy.
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Electrical & engineering
Steam Superheat Energy Calculator — Superheat Duty & Annual Energy
Calculate sensible superheat duty above saturation from steam flow, superheat temperature rise and entered vapor heat capacity.
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Electrical & engineering
Steam Desuperheating Water Calculator — Spray Water Flow & Outlet Steam
Estimate spray-water flow for steam desuperheating from a transparent steady-state energy balance.
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Electrical & engineering
Boiler Economizer Savings Calculator — Flue Heat Recovery & Fuel Savings
Estimate recoverable economizer duty, equivalent fuel input reduction and annual fuel-cost savings from feedwater temperature rise.
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Electrical & engineering
Boiler Feedwater Temperature Savings Calculator — Fuel & Cost Reduction
Quantify boiler fuel energy avoided when feedwater temperature increases at the same steam production rate.
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Electrical & engineering
Compressed Air Dryer Pressure Drop Cost Calculator — kW & Annual Cost
Estimate extra compressor power and annual electricity cost associated with dryer pressure drop using airflow and a user-entered specific pressure-power factor.
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Electrical & engineering
Compressed Air Aftercooler Duty Calculator — Sensible Cooling Load
Calculate approximate aftercooler sensible duty from air mass flow, inlet/outlet temperature and average Cp.
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Electrical & engineering
Heat Exchanger Fouling Resistance Calculator — Clean vs Dirty U-Value
Calculate added thermal fouling resistance and UA degradation from clean and dirty overall heat-transfer coefficients.
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Electrical & engineering
Steam Flash Vessel Sizing Calculator — Diameter from Vapor Velocity
Estimate minimum flash-vessel cross-sectional area and diameter from flash-steam mass flow, vapor specific volume and allowable superficial velocity.
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Electrical & engineering
Steam Drum Hold-Up Time Calculator — Usable Water Inventory & Ride-Through
Calculate usable drum water inventory and hold-up time from vessel geometry, usable level fraction, density and net drawdown rate.
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Electrical & engineering
Chiller Load Profile Energy Calculator — Bin kWh, Weighted kW/Ton & Cost
Calculate annual chiller energy and load-weighted efficiency from up to four operating bins with load fraction, hours and kW/ton.
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Time & dates
Day of Week Calculator — Weekday, ISO Week & Day of Year
Enter any valid calendar date to find its weekday, ISO week number, day of year and leap-year context without relying on a locale-specific date parser.
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Time & dates
Weeks Between Dates Calculator — Weeks, Days & Decimal Weeks
Calculate the elapsed calendar days between two dates as full weeks plus remaining days and decimal weeks, without silently adding an inclusive endpoint.
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Time & dates
Age Difference Calculator — Years, Months, Days & Total Days
Compare two birth dates or milestone dates and calculate the exact calendar gap in years, months and days plus total days and weeks.
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Time & dates
Years Between Dates Calculator — Exact Gap & Decimal Years
Calculate exact completed years, months and days between two dates, plus total days, weeks and an average-length decimal-year estimate.
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Time & dates
Leap Year Calculator — Check Any Gregorian Year
Check whether a year is a Gregorian leap year, see why the divisible-by-100 exception matters, and find the previous and next leap years.
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Time & dates
Days From Today Calculator
Add or subtract days, weeks or calendar months from today or any date, with curated direct-answer pages for common offsets.
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Choose the input that matches your question
A label or assumption can change a result: MB differs from MiB, square feet differ from linear feet, calendar days differ from business days, kVA differs from kW, and project estimates depend on real product inputs. Each calculator keeps those assumptions visible.
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