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Pump Hydraulic Power Calculator

Hydraulic kW = fluid density × standard gravity 9.80665 m/s² × flow in m³/s × differential head in metres ÷ 1,000.

210 / PUMP HYDRAULIC POWER

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Starting values are illustrative. Use your own costs, rates and assumptions.

INPUT GROUP 01

Entered quantities and model assumptions

Illustrative defaults are examples. Replace them with matching measurements, reviewed properties and actual quote terms.

Check the assumptions before acting on a result.

Read the method and example

YOUR CALCULATION

Follow an entered incompressible head duty through supplied efficiencies.

Hydraulic power · kW

1.961

Estimated pump shaft power · kW

2.452

Estimated electrical input · kW

2.724

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Illustrative inputs loaded. Replace them with your own assumptions.

How the pump hydraulic power calculator works

Hydraulic kW = fluid density × standard gravity 9.80665 m/s² × flow in m³/s × differential head in metres ÷ 1,000. Litres per second convert to m³/s by dividing by 1,000. Shaft power divides hydraulic power by pump efficiency; electrical input divides shaft power by motor efficiency.

Use actual incompressible flow, matching fluid density and total differential head on one energy boundary. Positive efficiencies are independently supplied at the entered duty. This ratio does not select a pump, establish NPSH/cavitation margin, certify a pressure rating or approve a safe installation.

Quantities use the stated units and finite bounded inputs. Whole purchases round up under the documented model; cost components round half-up to cents before totals are summed. Undefined ratios stay unavailable. π and logarithms use normal numeric precision. Display rounding does not alter the entered assumptions.

Worked example

10 L/s of a 1,000 kg/m³ fluid through 20 m head is 1.96133 kW hydraulic power. At 80% pump and 90% motor efficiency, electrical input is about 2.724 kW. Reducing head to 10 m halves hydraulic power to 0.980665 kW.

Sources and assumptions

The source material explains the underlying calculation or pricing structure. Entered prices, costs, schedules and scenario choices are your assumptions; this tool does not obtain supplier quotes or predict actual results.

  • Motor Efficiency Savings

    Convert the same mechanical shaft output through two entered efficiencies, then compare annual energy charges and simple payback.

  • Equipment Electricity Cost

    Estimate electricity use from input power, equipment count and operating time. Apply your energy rate and a separately entered monthly charge.

  • Pump Affinity Law Scenario

    For an ideal fixed-geometry centrifugal-pump similarity scenario, r = new speed / reference speed.

  • Reynolds Number

    Dynamic-property mode uses Re = density × velocity × characteristic length ÷ dynamic viscosity.

Calculation methods, testing and sources · Practical calculation guides