Pump Head & Power Calculator

Total head is the energy per unit weight the pump must add: static head (the vertical distance from the source surface to the delivery surface — suction lift plus discharge rise), friction head (losses in pipe and fittings, entered from your own pipe calculation), pressure head (any pressure required at the delivery point above the source, converted with p ÷ ρg), and velocity head (v²/2g at the discharge bore, if you give one; it is usually small and often ignored). Each term is listed separately so an estimate that dominates is visible.

Hydraulic power is the power delivered to the fluid: P = ρ g Q H. Dividing by the pump's efficiency at this duty point gives the shaft (brake) power the motor must supply; dividing again by the motor efficiency gives the electrical input. Both efficiencies come from the manufacturer's curves and vary with flow — there is no general value, so 100 % is only a placeholder that returns the theoretical minimum, and the page says so until you change it.

Friction loss depends on the pipe's roughness, the Reynolds number, every fitting and valve, and the pipe length — material data and system detail this page does not hold. Enter the figure from your pipe-loss calculation or supplier tables. Leaving it at zero is flagged, because a real pump sized on static head alone will not deliver the flow.

Metric uses m³/h, metres, bar, kg/m³ and kW; imperial uses US gal/min, feet, psi, lb/ft³ and horsepower (745.7 W). The density shown at first is a labelled water sample; enter your fluid's. NPSH, suction-side cavitation checks and pump selection are out of scope. Nothing leaves the browser; the same four anonymous usage counts as the rest of the site apply.