Pump Power Calculator
Calculate hydraulic output, required shaft input and losses from flow plus either pressure rise or pump head.
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Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Convert the selected flow, density and pressure or head to SI. Hydraulic power is pressure rise times volume flow; pressure and head are related through fluid density and standard gravity. Divide hydraulic power by the entered overall efficiency for required shaft input.
Ph=ΔpQ=ρgQH; H=Δp/(ρg); Pshaft=Ph/η
Worked example
At 120 L/min, a 300 kPa pressure rise and 75% overall efficiency give 0.6 kW hydraulic output and 0.8 kW required shaft input.
Assumptions and input details
Steady incompressible flow, uniform density and standard gravity 9.80665 m/s² are assumed. Overall efficiency is entered rather than inferred and must be greater than 0%. Head is energy per unit weight and therefore depends on the stated fluid density when converted to pressure. Pipe, valve, motor and drive losses are not added unless they are already represented by the entered efficiency and pump duty point. Check a pump curve and ratings before equipment selection.
References: US Department of Energy pump test procedure
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
Choose from 23 length definitions, including explicitly labelled regional measures. Area conversions square the length factor; geometric volumes cube it.
Regional measures are not interchangeable merely because their names look similar. This is a documented selection, not a claim to include every historical unit.
SI prefixes are explicit: for example, milli means one thousandth, micro one millionth and kilo one thousand. Changing a unit changes the interpretation of the entered number.
NIST measurement tables · Japanese traditional units · Mainland China and Hong Kong unit distinctions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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