Pool Pump Run Time Calculator
Set your pool volume and pump flow to see the daily run time in hours and minutes, plus how turnovers change the schedule.
| Turnovers | Hours per day |
|---|---|
| 1 | 6.3 h |
| 1.5 | 9.4 h |
| 2 | 12.5 h |
What a turnover means
One turnover is the time it takes the pump to move the whole pool volume through the filter once. It does not mean every drop is cleaned, since water mixes as it circulates, but it is the standard way to set a schedule. More turnovers per day mean clearer water and more time skimming the surface, at the cost of a higher power bill.
Find your real flow rate
The flow number on the pump box is a best-case rating at zero resistance. A real system with a filter, heater, and long pipe runs moves less. A flow meter gives the truest number, but the pump label plus a look at your filter pressure is a good start. If the pressure gauge sits high, the flow is lower than the rating and the run time needs to stretch.
Adjust by season and bather load
Warm water, strong sun, and a busy pool burn through chlorine fast, so two turnovers a day helps. In cool weather with a covered pool, one turnover or even less keeps the water clear. A variable speed pump can run a long, slow cycle that uses less power than a short, fast one, so match the speed to the job.
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Questions about this calculator
How many hours a day should I run my pool pump?
Most pools need enough run time for one to two full turnovers. At 40 GPM, a 15,000 gallon pool takes about 6.3 hours per turnover, so 6 to 12 hours a day covers most backyards. Larger pools and hot weather push that toward the higher end.
What is a pool turnover?
A turnover is one full pass of the pool volume through the filter. It is not a perfect cleaning, because water mixes, but it is a simple way to size a daily pump schedule. Two turnovers a day is a common target for a busy pool in summer.
How many turnovers per day does my pool need?
One turnover is the floor for clear water. One and a half suits a normal family pool, and two helps when the water is warm, the pool gets heavy use, or pollen is falling. Cool, covered pools can drop below one turnover and still stay clear.
How do I find my pump flow rate?
Look at the pump label for the rated gallons per minute, then discount it for real-world filter and pipe resistance. A flow meter gives the exact number. If your filter pressure runs high, your true flow is lower, so add run time to reach the same turnover.
Is it better to run a pool pump at night?
Running at night often means lower power rates and less evaporation loss. It also helps if you add chlorine after the sun goes down, since sunlight burns off unstabilized chlorine fast. The pump does not care about the clock, only the total run time.
Should I run my pool pump less in winter?
Yes. Cold water holds chlorine longer and algae grows slowly, so you can cut run time to one turnover or less. Keep enough circulation to move the chemicals and protect the equipment from freezing. A covered pool needs even less.
What if the calculator says more than 24 hours?
That means the pump cannot move the target volume in one day at that flow rate. Either raise the flow, pick fewer turnovers, or split the run into two sessions. If you cannot reach one turnover in a day, the pump is undersized for the pool or the filter is clogged.