Enter your pool volume and turnover goal to get a recommended flow rate (GPM) and pump horsepower range — in seconds, no email required.
Estimate only. Real sizing also depends on filter type, pipe diameter, and fitting count — a local pro can confirm exact sizing on-site.
Pool professionals size circulation around turnover — the time it takes to cycle your entire pool volume through the filter once. The formula:
GPM = Pool Gallons ÷ (Turnover Hours × 60)
Most residential pools target an 8-hour turnover. Utilities and the U.S. Department of Energy increasingly favor variable-speed pumps run longer at lower speed — a 10-hour turnover at low RPM often uses less total energy than an 8-hour turnover at full speed, while moving the same water. The horsepower figure above is a starting range only: the pump's actual rated flow at your specific head pressure (from pipe size, fitting count, and elevation) is what determines real-world performance, which is why two pumps with the same HP label can perform differently.
Not sure how to translate this into an actual pump model? Start with our buying guide, or if the pump you have right now is the problem, get a free repair quote and a local pro can size and install the replacement for you.
An oversized single-speed pump moves water faster than your filter and plumbing were designed for, wasting energy, increasing wear on fittings and the filter media, and running up your power bill for no water-quality benefit. Right-sizing (or moving to variable-speed) fixes all three.
It's a solid starting range for shopping, not a final spec. Head pressure from your specific plumbing run is the biggest variable it can't fully capture — a local pro or the pump manufacturer's flow curve chart will get you the last mile of precision.
For a rectangular pool: length × width × average depth × 7.5 = gallons. For irregular shapes, your pool's original builder paperwork or a service company can confirm it quickly.