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Pool Pump Calculator

Is your pump actually turning the water over? Do the math.

Cloudy water and algae usually trace back to filtration time, not chemicals — and filtration time is one division: gallons ÷ (GPM × 60). This calculator shows your actual turnover, the GPM needed to hit the 8-hour residential standard, and what each turnover costs in electricity (where the variable-speed-pump math gets persuasive).

Why people use this

Pool owners fighting cloudy water use this to find out whether the problem is runtime, not chemistry — one division tells you. The electricity cost layer makes the variable-speed upgrade math concrete: same turnover, a third of the watts.

How it works

1. Enter pool volume (use the Pool Volume calculator if unsure).
2. Enter your pump's actual flow rate — from the pump curve at your system head, not the box.
3. Pick the target turnover (8 hours is the residential standard).
4. Open the cost section for the monthly electricity number.

Common questions

How long should I run my pool pump?

Long enough for one full turnover minimum — for a 20,000-gallon pool on a 50 GPM pump that is 6.7 hours. Many owners run 8–12 hours in summer for margin. A variable-speed pump run longer at low speed filters better AND costs less than a single-speed sprint.

What GPM does my pump actually produce?

Less than the label. Nameplate GPM is at zero head pressure; real systems run 30–60 feet of head (plumbing, filter, heater). Find your pump's curve chart and read the flow at your estimated head — typically 60–70% of nameplate for a clean filter.

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