BTU Quick Reference Charts
Don't have a calculator handy? These quick reference charts can help you quickly choose the best heater size for your swimming pool.Â
BTU Requirements for Natural Gas and Propane Pool Heaters
| Pool Dimensions | Surface Area | Minimum BTU |
| 14' x 28' | 392 sq. ft. | 130,700 |
| 15' x 30' | 450 sq. ft. | 150,000 |
| 16' x 32' | 512 sq. ft. | 170,700 |
| 18' x 36' | 648 sq. ft. | 216,000 |
| 20' x 40' | 800 sq. ft. | 266,700 |
| 24' x 44' | 1,056 sq. ft. | 352,000 |
Hourly Temperature Increase: BTU vs. Surface Area of PoolÂ
| BTU | 300 sq. ft. | 400 sq. ft. | 500 sq. ft. | 600 sq. ft. | 700 sq. ft. | 800 sq. ft. | 1,000 sq. ft. |
| 100,000 | 1.25º | 1.0º | 0.75º | ||||
| 150,000 | 1.5º | 1.25º | 1.0º | 1.0º | 0.75º | ||
| 250,000 | 2.0º | 1.75º | 1.5º | 1.25º | 1.0º | 0.75º | |
| 350,000 | 3.0º | 2.5º | 2.0º | 1.5º | 1.25º | 1.0º | 0.75º |
| 400,000 | 3.5º | 2.75º | 2.5º | 2.0º | 1.5º | 1.25º | 1.0º |
Shop Residential Pool Heaters under 200k BTU
Shop Residential Pool Heaters over 200k BTU
BTU Requirements for Electric Heat Pumps
| Pool Size | Heat Pump Size |
| 15 ft Round | 50,000 - 70,000 BTU |
| 18 ft Round | 50,000 - 70,000 BTU |
| 21 ft Round | 50,000 - 85,000 BTU |
| 24 ft Round | 50,000 - 110,000 BTU |
| 27 ft Round | 100,000 - 120,000 BTU |
| 12 x 24 ft | 70,000 - 85,000 BTU |
| 16 x 32 ft | 110,000 - 120,000 BTU |
| 20 x 40 ft | 120,000 - 140,000 BTU |
Consider Gas Line Size
Before choosing a gas pool heater, check if your home's natural gas or propane setup can support it. The heater size depends on your existing gas line—larger heaters with higher BTU output require bigger pipes.
Upgrading your gas line increases installation costs and may require permits, a larger gas meter, and a home pressure regulator. Contact your gas utility provider for a field review to assess requirements. Manufacturers provide gas piping specs online, usually on product pages or their websites.