Pool Pump Size Calculator
Calculate the right pool pump size for your swimming pool.
gallons
Total pool water volume in gallons
ft
Friction loss from plumbing, filter, heater, etc.
Required GPM = Pool Volume (gallons) / (Turnover Hours × 60)
Example: 20,000 gallon pool with 8-hour turnover needs 42 GPM pump. With 1.5 HP pump, you'll get ~2,500 GPH flow (good circulation)
What is pool turnover?
Turnover is the time to circulate the entire pool volume through the filter once. Most pools need 1-2 turnovers per day. 8 hours is standard for residential pools.
What size pump do I need?
It depends on pool volume, plumbing size, and head pressure. Bigger isn't always better—oversized pumps waste energy and can damage equipment.
📐 Formula
Required GPM = Pool Volume (gallons) / (Turnover Hours × 60)
📝 Example Calculation
Example: 20,000 gallon pool with 8-hour turnover needs 42 GPM pump. With 1.5 HP pump, you'll get ~2,500 GPH flow (good circulation)
❓ Frequently Asked Questions
What is pool turnover?▼
Turnover is the time to circulate the entire pool volume through the filter once. Most pools need 1-2 turnovers per day. 8 hours is standard for residential pools.
What size pump do I need?▼
It depends on pool volume, plumbing size, and head pressure. Bigger isn't always better—oversized pumps waste energy and can damage equipment.