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Pump Power Calculator

Compute hydraulic, shaft, and motor input power from flow rate, total head, fluid density, and efficiencies. Outputs in W, kW, and HP. Metric / imperial unit selection per field.

Inputs Saved

Δp inputs are converted to head using the chosen fluid density.
Recommended motor size = motor input ÷ ηm × SF (typically 1.10–1.25).

Formula. Hydraulic Ph = ρ·g·Q·H. Shaft Ps = Ph / ηp. Motor input Pm = Ps / ηm. g = 9.80665 m/s².

Results

Recommended Motor Size
Includes pump & motor losses + service factor
Hydraulic Power
kW
Shaft Power
kW
Motor Input Power
kW
Overall Efficiency
%

Use this for preliminary sizing only. Final motor selection should account for NPSHa, viscosity correction, starting torque, ambient temperature, duty cycle, and standard motor frame sizes.