Swimming Pool Heater Size Calculator

To help estimate the pool heater size, enter all of your information regarding your pool.

Use the swimming pool heater size calculator below. Click calculate to get your

Please note that heat rise varies when dealing with different heaters. The usual recommendation is an increase of 1 to 1 and a half degree per hour.


  • Calculations are rough estimates as to which size pool heater you may need.
  • Consult with a certified pool installer to verify the minimum heater size required
  • Most newer heaters are at least 83% efficient.
  • Heaters manufactured prior to 1996 are 78% efficient.

We recommend you size your heater one size larger than required. Shop swimming pool heaters from our online store. Get Free Shipping!


Surface area of pool (Sq. ft):


Efficiency of heater (%):


Desired temperature rise (F):


Wind (mph):


Required Natural Gas Heater Output (BTU/Hr.):
Minimum Natural Gas Heater Size Required:
Required Propane Heater Output (BTU/Hr.):
Minimum Propane Heater Size Required: