Pump hydraulic power
Water or another liquid, steady flow. Pipe losses are not calculated here — put the head you already have.
Method
P = ρgQH. Worked case: 0.02 m³/s, 15 m, water, 70% gives 2.94 kW hydraulic and 4.20 kW shaft.
Not a system curve, NPSH check or manufacturer selection.
Logic: how this figure is built.
How to read a pump power
Hydraulic power is ρgQH. A flow of 0.02 m³/s against 15 m of head, in water, is about 2.94 kW. Shaft power is that figure divided by the pump efficiency you type. The page does not know the efficiency of a real pump.
Head is the head the pump must provide, including static lift and losses, if that is what you typed. A static lift alone understates the duty. Flow is the volume per second at the duty point, not a daily volume.
Efficiency is an input. 70% is a screen, not a selection. Motor power sits above shaft power by the motor efficiency, which is not on this page.
Use it to see the order of a duty before a mechanical selection. It is not a pump curve and not a net-positive-suction-head check.
- Related: pipe velocity
- mechanical guide
Last checked 3 October 2026. A scenario, not a design. See methodology, standards and the disclaimer.