Pool Pump Run Time Calculator
How many hours a day should your pool pump run? Calculate the turnover time from pool volume and pump flow, the daily run time for 1–2 turnovers, the electricity used and the monthly cost.
How it works
turnover time (h) = pool volume ÷ (flow rate × 60) · run time = turnover time × turnovers per day · energy = run time × pump kW · cost = energy × price
A turnover is the time the pump needs to push the whole volume of the pool through the filter once. Residential pools should get at least one turnover a day — many health codes require a 6–8 hour turnover for public pools — and 1.5–2 turnovers in hot weather, heavy use or when algae appears. Running time therefore depends on the real flow, which is lower than the rated maximum once pipes and a dirty filter add resistance. Two-speed and variable-speed pumps run longer at low speed but use far less energy, because pump power falls with roughly the cube of speed.
Worked example
A 50,000 L pool with a pump moving 200 L/min: one turnover takes 50,000 ÷ 200 ÷ 60 = 4.2 hours, so for one turnover a day run it 4.2 hours. A 1,100 W pump uses 4.6 kWh a day, about $0.69 a day or $20.63 a month at $0.15/kWh.
Sources: US Department of Energy — Energy-efficient pool pumps · CDC Model Aquatic Health Code — turnover times
Frequently asked questions
How many hours a day should I run my pool pump?
Long enough for at least one full turnover — for most home pools 6–8 hours with a single-speed pump. Divide the pool volume by the pump’s real flow per hour to get your number, and add time in hot weather or after heavy use.
Is it better to run the pool pump at night or during the day?
Run it during the day when the sun breaks down chlorine and algae grow, or at least split the time. Some utilities have cheaper night rates, so running part of the cycle at night can save money.
How do I find my pump’s flow rate?
Use a flow meter on the return line, or read the pump curve for your pipe size and total dynamic head. As a rough guide, real flow is often 60–80% of the maximum on the label.
Do variable-speed pumps save money?
Yes. Halving the speed cuts power to roughly one-eighth while halving flow, so running twice as long at low speed uses about a quarter of the energy for the same turnover.
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This calculator is for educational purposes. Double-check important results before acting on them.