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.
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 Pool
| 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 the Gas Line Size
When selecting a gas pool heater, it's important to also consider your home's current natural gas or propane setup. If a gas line is already installed, you'll need to make sure it can accommodate your chosen heater. Your choice of heater will be limited by the size of the available gas line — a larger pipe size is necessary for larger heaters with a higher BTU output.
If you need to upgrade your gas line to accommodate a larger heater, your cost of installation will go up, and you may need to get a permit to complete the job. A larger gas meter and home pressure regulator will also be required. We suggest contacting your local gas utility provider to request a field review once you've identified the heater and gas line size needed. From there, they can help with determining your next steps. Each heater manufacturer carefully details the gas piping requirements needed for optimal function, and this info can often be found online through the product page or manufacturer's website.