Pool Pump Run Time Calculator
Work out how long to run your pump to turn over the water, plus the daily energy cost.
A turnover is one full cycle of your pool's water through the filter. Divide total gallons by the pump's flow (we convert GPM to gallons per hour by multiplying by 60) to get the hours for each turnover. Most pools do fine with one turnover a day; run two in peak heat or heavy use. A variable-speed pump moves less water per hour but sips far less power.
How it works
A turnover is one complete pass of all your pool water through the filter. Circulating the whole volume keeps the water clear, spreads chemicals evenly, and stops dead spots where algae likes to settle.
The run time is just your pool's gallons divided by the pump's flow in gallons per hour. If you know flow in gallons per minute, we multiply by 60 first. Want two turnovers a day? Double the hours.
A 15,000-gallon pool with a pump pushing 50 GPM moves 3,000 gallons an hour, so one turnover takes about 5 hours. We also multiply the pump's power draw by those hours and your electricity rate to show the daily running cost — where a variable-speed pump really pays off by moving less water per hour for far fewer watts.
Frequently asked questions
One turnover or two?
One turnover a day is plenty for most residential pools with normal use. Bump it to two during a heat wave, after heavy swimming, or while fighting an algae bloom, when you want the water filtered more aggressively.
Where do I find my pump's flow rate?
Check the pump or filter label, or the equipment manual — it's often given in GPM at a typical head pressure. If you only know horsepower, a rough single-speed guide is around 40 to 60 GPM, but the real number depends on plumbing and filter size.
How does a variable-speed pump change this?
Running slower moves fewer gallons per hour, so you need more hours for a turnover, but power use drops with the cube of speed. Halving the speed roughly quarters the wattage, so long slow runs usually cost far less than short fast ones.