Well Pump Calculator
Size a submersible well pump from depth, flow demand and pressure requirement.
About Well Pump Calculator
Total dynamic head combines the physical lift, the pressure the system must deliver and friction in the pipework. Because power scales with both flow and head, an oversized pump wastes energy continuously. Head rather than depth determines pump selection, and the pressure component alone can add thirty metres of equivalent lift on a domestic system.
Formula
Well Pump
Power = ρ·g·Q·H ÷ efficiency, where H is total dynamic head
- total dynamic head
- Lift depth plus pressure head plus friction losses
- pressure head
- One bar is about 10.2 metres of water column
Worked example
With the default values below, Well Pump Calculator returns Pump Power Required of 0.668. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Pump setting depthminimum 1 m
- 60 m
- Fixtures servedminimum 1
- 12
- Target system pressureminimum 0.5 bar
- 3.5 bar
- Horizontal pipe runminimum 0 m
- 40 m
- Pump efficiencyaccepts 10–95 %
- 60 %
Results
- Pump Power Required
- 0.668 kW
- Design Flow
- 24.78 L/min
- Total Dynamic Head
- 98.90 m
- Pressure Head Component
- 35.70 m
- Pump Power Required
- 0.896 hp
Step by step
- 1Values used
- 2Well Pump
- 3Pump Power Required= 0.668 kW
- 4Design Flow= 24.78 L/min
- 5Total Dynamic Head= 98.90 m
- 6Pressure Head Component= 35.70 m
- 7Pump Power Required= 0.896 hp
Assumptions and limits
- The result is derived only from the 5 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Well Pump calculated?
Power = ρ·g·Q·H ÷ efficiency, where H is total dynamic head Total dynamic head combines the physical lift, the pressure the system must deliver and friction in the pipework. Because power scales with both flow and head, an oversized pump wastes energy continuously.
Why does Well Pump matter?
Head rather than depth determines pump selection, and the pressure component alone can add thirty metres of equivalent lift on a domestic system.
What values do I need to enter?
This calculator takes 5 inputs: Pump setting depth, Fixtures served, Target system pressure, Horizontal pipe run, Pump efficiency. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.