⏱️ Pool Filter Run Time Calculator
Calculate how many hours per day you need to run your filter pump to achieve one full turnover of your pool water, based on your pump's actual flow rate.
One turnover, in hours
Flow is given in gallons per minute, so it is multiplied by 60 to get gallons per hour before dividing into the pool volume:
run hours = pool gallons / (pump GPM × 60)The defaults are a 16,830 gallon pool and a pump moving 40 GPM, which is 2,400 gallons an hour and 7.0 hours to push the whole pool through the filter once. That is one turnover, not one pass per drop of water - mixing means some water recirculates while some has not been through yet.
Flow rate is the input that decides everything
The same 16,830 gallon pool changes completely with the pump:
| Actual flow | Hours for one turnover |
|---|---|
| 30 GPM | 9.4 |
| 40 GPM | 7.0 |
| 60 GPM | 4.7 |
| 80 GPM | 3.5 |
Enter the flow you actually get, not the number on the pump label. Pipe runs, elbows, a dirty filter and heater all add resistance, so a pump rated at 60 GPM often delivers 40 to 45 once installed. A flow meter reads it directly.
Frequently asked questions
How many hours a day should I run my pool pump?
One turnover is the usual baseline, so 7.0 hours for a 16,830 gallon pool at 40 GPM. In hot weather, after heavy swimmer use or while algae is being cleared, plan on one and a half to two turnovers.
Does the run time have to be in one block?
No. Only the daily total matters to the arithmetic, so splitting 7 hours into a morning and an afternoon block filters the same volume and keeps the water moving across more of the day.
Why does a variable speed pump need longer?
Because it is moving less water per minute. Halving the speed roughly halves the GPM and doubles the hours, but power draw falls much faster than flow, so the longer run still costs less to complete.