Pool heater BTU calculator
PROBTU/hr to heat a pool to your target temperature.
Inputs
Result
BTU/hr
139,000
Heater size (nearest 50k)
150k BTU
The formula
BTU/hr = (gal × 8.34 × ΔT) ÷ hours.
Worked example
20,000 gal × 20°F ÷ 24 hr = 139,000 BTU/hr.
Frequently asked
›Gas vs heat pump?
Gas heats fast; heat pumps are 4–5× more efficient long-term.