Work out booster pump pressure instantly with clear inputs, formula shown and shareable results.
A booster only has to make up the shortfall. Required outlet pressure plus the static penalty of lifting water to the highest fixture, less the pressure already available at the inlet, gives the boost. One psi lifts water 2.31 feet, so the conversion runs both ways.
Boost required
Boost psi = required psi + height ft / 2.307 - inlet psi
Power
WHP = GPM x boost head ft / 3960
Boost psi = required psi + height ft / 2.307 - inlet psi. A booster only has to make up the shortfall.
On peak, because inlet pressure sags exactly when demand is highest. Sizing on average flow leaves top-floor fixtures starved at the morning peak.
This calculator takes 4 inputs: Inlet pressure available, Pressure required at outlet, Height gain to highest outlet, Design flow. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.