Skip to main content

Pool Pump Size Calculator

Reviewed 2026-04

What size pump does your pool need? Estimate the flow needed for a chosen turnover time, then select equipment using actual system and pump curves.

Built on CDC and ANSI pool-water standards

Already have a pump? See how long to run it each day → Pump Run Time Calculator

Don't know? Use our Volume Calculator →

Confirm your inputs

Examples remain unconfirmed until you check each value. Confirm fresh test results and your measured pool volume before using a dose. Editing a value clears its confirmation.

Shopping for a pump?

We are not naming models. Pump lines get discontinued while retail listings outlive them, and this is the most expensive thing on the site — so choose on your own numbers. Fill in the form for your required flow, then work through the selection checklist.

Frequently asked questions

What does this pump sizing calculator establish?

It estimates the flow needed to pass the entered pool volume through the system within the chosen time. It does not identify a pump model or horsepower. Turnover alone does not establish sanitation or filtration performance.

How do I choose an actual pump?

Use an identified model and RPM curve at the actual system head, considering pipework, fittings, filter condition and equipment. Head changes with flow; a discharge gauge alone does not establish it. A qualified installer can measure suction and discharge conditions and check required minimum and maximum flows.

What about salt cells and heaters?

Their manuals specify flow and operating constraints. A volume-based flow estimate cannot replace those limits. Ensure the selected pump and operating speed meet every active device’s requirements.

Pump Run Time Calculator →Volume Calculator →How to choose a variable-speed pump →

How we calculate this
Our formulas follow ANSI pool-water standards and are validated against CDC pool-water health code guidelines. We show you the math so you can verify every result. Questions or corrections? Please contact us.