Pump Head Calculator
Calculate total dynamic head for pump sizing from static lift height and estimated friction loss in the piping.
How this calculator works
A pump doesn’t just fight gravity — it also fights the resistance of the pipe it’s pushing water through. This calculator adds the actual vertical lift the pump has to overcome to the equivalent resistance created by pipe friction, giving the total head a pump needs to be rated for.
Formula: Total dynamic head (TDH) = static head + friction head loss. Static head is the actual vertical lift (elevation change) the pump must overcome; friction head loss is the additional equivalent height lost to pipe friction, fittings, and valves (find it with the Pipe Friction Loss Calculator, converting pressure loss in psi to feet of head by multiplying by 2.31).
Worked example
20 ft of static lift plus 5 ft of friction head loss:
- Static head: 20 ft
- Friction head loss: 5 ft
- Total dynamic head: 20 + 5 = 25 ft
Notes
A pump must be selected to deliver its target flow rate at this total dynamic head, not just at zero head. Every pump’s performance curve shows flow dropping as head increases, so undersizing the head estimate leads to a pump that can’t actually deliver the flow you need once it’s fighting the real elevation and friction losses.
How to use
Enter your static lift height and your estimated friction head loss (use the Pipe Friction Loss Calculator first if you only have a psi figure). The calculator adds them together to give total dynamic head, which you then check against a pump’s performance curve at your target flow rate.
A planning estimate using standard hydraulics formulas. For code-governed drainage or civil design, confirm with a licensed civil engineer.
Frequently asked questions
What is total dynamic head?
Total dynamic head, or TDH, is the total resistance a pump must overcome, expressed as an equivalent height of water in feet. It combines static head, the actual vertical lift from source to destination, with friction head loss, the extra resistance created by pipe walls, fittings, and valves along the way.
How is static head different from friction head?
Static head is a physical measurement: the actual elevation change between the water source and where it needs to go, regardless of the piping. Friction head is not a physical height at all, but the equivalent height of resistance created as water rubs against pipe walls and passes through fittings, valves, and bends.
How do I estimate friction head loss for my system?
Friction head loss is typically calculated separately using a pipe friction loss calculator, which factors in pipe diameter, length, material, and flow rate to produce a pressure loss in psi. That psi figure converts to feet of head by multiplying by 2.31, giving the friction head value to add to static head.
Why does total dynamic head matter for choosing a pump?
Every pump has a performance curve showing that its flow rate drops as head increases — a pump does not deliver the same GPM at high head that it does at zero head. Sizing a pump using only static height and ignoring friction losses risks choosing one that cannot actually deliver the flow you need once installed.
Estimates only. Verify quantities with your supplier before purchasing.