How much head does your pump need?
Enter the static lift, the pipe friction loss and any pressure you need at the outlet — get the total dynamic head (TDH) instantly, in feet or metres, ready to read off a pump curve.
The pump has to develop about this much head at your design flow. Match it against a pump's performance (pump) curve at that flow — pick a pump whose curve sits at or a little above this point.
TDH = static lift + friction loss + pressure head, added in feet or metres of water. 1 bar ≈ 10.2 m of head. Velocity head is tiny and is conventionally left out. Set outlet pressure to 0 if you only need to raise water to a height.
Want the full method, a psi-to-feet conversion table and worked examples? Read: how to calculate total dynamic head →
Common questions
- How do you calculate total dynamic head (TDH)?
- Add the three heads a pump works against: TDH = static lift + friction loss + pressure head. Static lift is the vertical height the water is raised (source level to discharge). Friction loss is the head lost to friction in the pipe and fittings at your design flow. Pressure head is any pressure that must remain at the outlet, converted to a height of water (1 psi ≈ 2.31 ft, 1 bar ≈ 10.2 m). Enter the three figures above and the calculator adds them in feet or metres.
- What is total dynamic head on a pump?
- Total dynamic head (TDH) is the total equivalent height of water a pump must lift against when it is running — not just the physical rise, but the friction in the pipework and any pressure it has to maintain at the far end, all expressed as one number in feet or metres of head. It is the figure you take to a pump's performance curve to choose a pump, read at your design flow rate.
- What is the difference between static head and dynamic head?
- Static head is just the vertical distance the water is raised, measured with no flow. Dynamic head (TDH) is what the pump actually sees while it is moving water: the static lift plus the friction loss the flow creates plus any pressure held at the outlet. Static head is always part of TDH, but on a long or small-bore run the friction and pressure parts can be larger than the lift itself.
- How do you convert psi to feet of head?
- For water, feet of head = psi × 2.31 (because one foot of water column is about 0.433 psi). So 20 psi is about 46 feet of head, and 40 psi is about 92 feet. In metric, 1 bar is about 10.2 metres of head. The calculator does this conversion for the pressure you enter, so you can mix a lift in feet with a required pressure in psi.
- Does pipe size affect pump head?
- Yes — through the friction-loss part. A smaller bore or a longer run means more friction loss, which raises the TDH and forces a bigger pump. Work out that figure with the friction loss calculator (it accounts for flow, bore, length and material) and put the result in the friction-loss box here. The static lift and outlet pressure do not change with pipe size.
Reference & education only. Not professional, engineering, or code-compliance advice. Estimates are based on published model codes; local amendments and your Authority Having Jurisdiction (AHJ) govern. Always verify against the current adopted code and a licensed professional before doing work.
Last reviewed 2026-07.