Calculator
Pump Power Calculator
Change the inputs; results update automatically.
Formula
P_shaft(kW) = (rho x g x Flow(m3/s) x H(m)) / (1000 x efficiency) = (Q(m3/h) x H(mSS)) / (367 x efficiency) Worked example
10 m³/h, 25 m head and efficiency 0.70 give about 0.97 kW of shaft power. Motor losses are separate.
Scope and interpretation
The model assumes water density 1000 kg/m³ and g = 9.81 m/s². Verify the pump curve and NPSH separately.