Formula & worked example
Ph=ρgQH; ηwire=Ph/Pwire; ηpump≈ηwire/ηmotor.
100 m³/h water at 30 m head produces about 8.17 kW hydraulic power. With 12 kW measured electrical input, wire-to-water efficiency is about 68.1%.
Plant utility calculator · Updated Sep 17, 2026
Pump Wire-to-Water Efficiency Calculator — Hydraulic Power, Pump & Motor Losses
Calculate hydraulic output, wire-to-water efficiency, estimated pump efficiency after motor losses, wasted electrical power and annual loss cost from measured flow, head and electrical input.
Inputs
Live engineering result
Hydraulic output 8.1558639 kW
Wire-to-water efficiency 67.965533%
Estimated pump efficiency 73.875579%
Electrical-to-hydraulic loss 3.8441361 kW
Annual indicated loss 19.22068 MWh
Annual indicated loss cost 2,306.4817
Assumptions & limits
- Use simultaneous stabilized flow, head and true electrical input measurements.
- Estimated pump efficiency depends on the entered motor efficiency; direct shaft-power measurement is preferable when available.
Frequently asked questions
What does this Pump Wire-to-Water Efficiency Calculator calculate?
Calculate hydraulic output, wire-to-water efficiency, estimated pump efficiency after motor losses, wasted electrical power and annual loss cost from measured flow, head and electrical input.
Is this enough for final equipment selection?
Use it for screening and comparison. Final plant selection should be checked against manufacturer data, actual operating profiles and applicable engineering requirements.
Why are the assumptions shown?
Plant utility calculations are sensitive to pressure basis, efficiency, duty cycle and operating cost assumptions. Showing them makes the result easier to audit and revise.