Calculator collection · 306 distinct tools
Electrical & Engineering Calculators
Solve foundational voltage, current, resistance and power relationships without hiding the formulas.
Electrical pages separate real power, apparent power, current, voltage, power factor, efficiency and ideal component relationships. Formula results are calculation aids—not conductor, breaker or code-compliance recommendations.
Open a real interactive tool instead of landing on a thin keyword page.
Formulas, units and assumptions stay visible beside the result.
Move between genuinely different calculations inside one collection.
Supplier, manufacturer, drawing and standards data remain authoritative where required.
Choose the calculation that matches the job
Each page owns a distinct input/output task. Reciprocal forms stay together when the underlying job is the same.
Calculator
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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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 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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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Transformer kVA Calculator — Single & Three Phase Load Sizing
Calculate load kVA from voltage and current for single or balanced three-phase systems, then apply an explicit spare-capacity percentage.
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Power Factor Correction Calculator — Required Capacitor kVAR
Calculate ideal capacitor reactive power needed to move a real-power load from an initial to a target displacement power factor.
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Battery Runtime Calculator — Ah, Wh, DoD & Efficiency
Estimate battery runtime from amp-hours, voltage, load power, usable depth of discharge and system efficiency with all assumptions visible.
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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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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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LED Resistor Calculator — Series Resistance & Power
Calculate a current-limiting resistor for one or more series LEDs from supply voltage, forward voltage, target current and whole-number LED count.
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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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Transformer Turns Ratio Calculator — Voltage, Current & Apparent Power
Solve an ideal transformer from primary and secondary turns, primary voltage and current. Get turns ratio, secondary voltage/current, apparent power and step-up or step-down classification.
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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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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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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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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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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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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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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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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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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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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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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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Coaxial Cable Impedance Calculator — Geometry & Dielectric
Estimate coax characteristic impedance from inner-conductor diameter, shield inner diameter and relative permittivity.
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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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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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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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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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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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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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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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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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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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Prandtl Number Calculator — Viscosity, Heat Capacity & Thermal Conductivity
Calculate Prandtl number from dynamic viscosity, specific heat and thermal conductivity.
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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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Fin Efficiency Calculator — Straight Rectangular Fin
Calculate adiabatic-tip straight-fin efficiency from convection coefficient, conductivity, thickness and length.
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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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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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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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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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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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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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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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Compressor Power Calculator — Isentropic Gas Compression
Estimate ideal and shaft power plus discharge temperature for ideal-gas isentropic compression.
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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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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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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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Drag Force Calculator — Fluid Dynamic Drag
Calculate aerodynamic or hydrodynamic drag from density, velocity, drag coefficient and reference area.
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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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Move to a different formula only when the next question actually changes.
Voltage Drop Calculator
Calculate forward voltage drop or reverse-solve run, current or conductor area.
Electricity Cost Calculator
Move from power and runtime to kWh and an editable energy tariff.
Frequency ↔ Period Calculator
Move between frequency and period before timing or RC calculations.
Ohm's Law Calculator
Solve voltage, current, resistance and ideal resistive power relationships.
Explore adjacent calculator collections
Cross-cluster links help you move from measurement to project quantity, electrical relationships, money, statistics or media planning without flattening everything into one giant list.
Measurement Calculators →
Work with tape-measure dimensions, drawing scales, area and unit conversions.
Construction & DIY Calculators →
Estimate area, concrete and tile quantities with visible assumptions and formulas.
Statistics 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.
Fraction Calculators →
Work with fractions, decimals, mixed numbers and practical inch fractions with the simplifying steps kept visible.
Geometry Calculators →
Solve common 2D area, right triangles, general triangles, circles, rectangles, perimeter, volume and slope from explicit dimensions and formulas.
Screen, Image & Video Calculators →
Plan pixel density, physical screen dimensions, aspect ratios, video bitrate and file size before resizing, converting or compressing media.
Money & Business Calculators →
Model debt payoff, debt-to-income ratios, investment fee drag, discounted cash flows, IRR and sales commission with assumptions and working exposed.
Everyday Planning Calculators →
Solve practical planning, weather, science, logistics and engineering jobs with editable assumptions and visible working.
Formula first, assumptions visible
MAXScanner keeps editable rates, units and dimensions next to the result, shows the working where it helps, and avoids turning reciprocal formulas into duplicate pages. Product documents, financial terms, study design, drawings and applicable standards remain authoritative where required.