Booster Pump Pressure Calculator

Work out booster pump pressure instantly with clear inputs, formula shown and shareable results.

About Booster Pump Pressure Calculator

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.

Formulas

Boost required

Boost psi = required psi + height ft / 2.307 - inlet psi

Power

WHP = GPM x boost head ft / 3960

Worked example

With the default values below, Booster Pump Pressure Calculator returns Pressure boost required of 48.01. Change any input above and every figure here is recalculated in your browser.

Inputs used

Inlet pressure availableminimum 0 psi: 25 psi
Pressure required at outletminimum 0 psi: 60 psi
Height gain to highest outletminimum 0 ft: 30 ft
Design flowminimum 0.1 GPM: 20 GPM

Results

Pressure boost required: 48.01 psi
Boost expressed as head: 110.7 ft
Hydraulic power: 0.559 hp
Motor power at 60 percent efficiency: 0.695 kW

Step by step

1Values used
2Boost required
3Power
4Pressure boost required= 48.01 psi
5Boost expressed as head= 110.7 ft
6Hydraulic power= 0.559 hp
7Motor power at 60 percent efficiency= 0.695 kW

Assumptions and limits

The result is derived only from the 4 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 the Booster Pump Pressure figure worked out?

Boost psi = required psi + height ft / 2.307 - inlet psi. A booster only has to make up the shortfall.

Should the boost be sized on peak or average flow?

On peak, because inlet pressure sags exactly when demand is highest. Sizing on average flow leaves top-floor fixtures starved at the morning peak.

What values do I need to enter?

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.