Pool Heater Size Calculator
Estimate pool heater size from entered measurements.
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What this tool does
Estimate pool heater size from entered measurements. Sensible heating only; evaporation, surface losses, climate and wind can require substantially more capacity.
How to use the Pool Heater Size Calculator
- Enter or select pool volume in gal.
- Enter or select desired temperature rise (°f difference).
- Enter or select heat-up time (hours).
- Enter or select heater efficiency (%).
- Read the calculated result; change any measurement to compare alternatives.
Formula
input BTU/hour=gallons×8.34×temperature rise/(hours×efficiency/100)
- volume
- Pool volume (gal, before metric conversion)
- rise
- Desired temperature rise (°F difference)
- hours
- Heat-up time (hours)
- efficiency
- Heater efficiency (%)
Sensible heating only; evaporation, surface losses, climate and wind can require substantially more capacity.
Worked example
For pool heater size calculator, the following measurements illustrate the exact method: Pool volume: 15000; Desired temperature rise (°F difference): 10; Heat-up time (hours): 24; Heater efficiency (%): 85.
Inputs
- Pool volume15000 gal
- Desired temperature rise (°F difference)10
- Heat-up time (hours)24
- Heater efficiency (%)85
Result
- Minimum heater input (BTU/hour)61,323.53
Results explained
- Minimum heater input (BTU/hour)
- Minimum heater input (BTU/hour) from the formula above. Sensible heating only; evaporation, surface losses, climate and wind can require substantially more capacity.
Frequently asked questions
input BTU/hour=gallons×8.34×temperature rise/(hours×efficiency/100)
Sensible heating only; evaporation, surface losses, climate and wind can require substantially more capacity.
Verify dimensions, product concentration and equipment instructions. Use a qualified pool professional for final chemical dosing and equipment sizing.
No. The entered figures are processed only in your browser.
Follow each input's unit label. Imperial and metric switching converts the labelled geometry and volume measurements.