Pool Pump Size Calculator

What size pool pump do I need?

gal
hours

Your pump should move

37.5gallons per minute

Volume รท turnover. Energy rules cap residential filtration at a 6-hour turnover or 36 gpm, whichever is higher. Match the pump curve to your plumbing head with a pool pro.

Pump flow against the filtration limitLimit 50 gpmFlow needed: 37.5 gpm
Per hour2,250 gal
Maximum filtration flow50 gpm

Turn your pool gallons and turnover target into a flow rate you can compare with a pump curve.

How it works

Gallons divided by turnover hours and 60 gives gallons per minute. A 6-hour turnover or 36 gpm is the usual maximum for residential filtration under energy rules.

Before you order

  • Choose a pump by its curve at your system head, since horsepower alone is a poor guide.
  • Variable-speed pumps use far less energy at low speed.
  • Match filter and heater flow limits to the pump.

Common questions

How long should I run the pump?

Long enough for at least one turnover a day, more in hot weather or heavy use.

How do I figure head?

Use your plumbing runs and fittings or have a pool pro measure pressure at the filter.