Skip to main content

Find your next tool

DashboardAndroid app
Language
Appearance

Plant Engineering Calculator

Updated Sep 18, 2026

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.

Live calculationWorking shownPrivate in browser

Inputs

Results

Electrical input 26.15 kW
Hydraulic power 19.61 kW
Annual energy 156906 kWh
Annual cost $15691
Annual volume 1080000 m³
Cost per 1,000 m³ $14.53
More actions

Shared links reopen these inputs. Recent and saved calculations stay in this browser unless you clear site data.

Formula

P=ρgQH/η; annual cost=P×hours×tariff.

Your calculation, step by step

These steps use the values currently entered above so the result can be checked independently.

  1. 1.Convert flow: 50.000 L/s ÷ 1000 = 0.050000 m³/s.
  2. 2.Hydraulic power = ρgQH = 1000.00 × 9.80665 × 0.050000 × 40.00 ÷ 1000 = 19.6133 kW.
  3. 3.Electrical input = 19.6133 ÷ (75.00% ÷ 100) = 26.1511 kW.
  4. 4.Annual energy = 26.1511 × 6000 = 156906.4 kWh; cost = 156906.4 × $0.1000 = $15690.64.
  5. 5.Pumped volume = 50.000 × 3.6 × 6000 = 1080000.0 m³/year; normalized cost = $14.528 per 1,000 m³.

How to use this calculator

  1. Enter measured or design values using the units shown beside each field.
  2. Review the live results and the substituted calculation steps before using the estimate.
  3. Check the assumptions below, then continue to a related calculator when the next engineering decision needs another model.

Worked example

A 50 L/s water pump at 40 m head and 75% overall efficiency needs about 26.2 kW input before annualization.

Assumptions and limits

  • Overall efficiency should include pump and motor losses for electrical cost.
  • Actual duty can vary across the system curve; use a load profile for variable duty.

How to interpret the result

Treat the primary result as an engineering screening value, then use the secondary outputs to understand scale, energy or operating impact. Confirm site measurements, equipment limits and applicable standards before making a design or control change.

Questions engineers ask

Should pump efficiency include the motor?

For electricity cost, use an overall wire-to-water efficiency or otherwise include both pump and motor losses. Using pump hydraulic efficiency alone understates the electrical input that is billed.

Why convert L/s to m³/s before the power formula?

The SI hydraulic-power relationship ρgQH uses Q in m³/s. The calculator explicitly converts L/s by dividing by 1,000 before calculating hydraulic power, then divides by overall efficiency for electrical input.

Can one duty point represent annual pump cost?

Only when the entered point and equivalent hours reasonably represent operation. Variable-speed or varying-system pumps should use a load/duty profile because flow, head and efficiency change across the year.

Continue the calculation

Use the next calculator in the same engineering workflow instead of restarting from search.

pump powerpump system curvepump throttling loss
Methodology. MAXScanner shows the governing formula, entered values and calculation outputs so the estimate is auditable. The calculator is a screening aid; assumptions and equipment-specific limits remain part of the engineering review.