Estimate cost per hour/day for natural gas or propane heating.
This calculator estimates natural-gas or propane usage from the heater’s BTU-per-hour rating, efficiency, fuel price, and runtime. It converts the heater’s energy demand into therms of natural gas or gallons of propane and shows the estimated cost per hour and total cost for the selected runtime.
The result assumes the heater runs continuously at its rated output. Actual operation may cycle on and off after the pool reaches the set temperature.
Heating cost depends on more than heater size. Wind, evaporation, air temperature, water temperature, pool surface area, humidity, and cover use all affect heat loss. An uncovered pool on a cool, windy night can lose heat almost as quickly as the heater adds it.
Natural gas is usually billed by the therm, while propane is sold by the gallon. Propane contains about 91,500 BTU per gallon, and one natural-gas therm represents about 100,000 BTU. Local fuel prices determine which option costs more to operate.
A larger heater burns more fuel per hour, but it may reach the target temperature faster. Total cost depends on runtime and heat loss, not only the BTU rating.
A cover can greatly reduce evaporation, which is usually the largest source of heat loss. That can reduce both heating time and the cost of maintaining temperature.
Fuel prices, weather, heater cycling, equipment condition, and real efficiency all affect the final bill.
No. This tool estimates fuel cost for a known runtime. Use a heater-sizing or heating-time calculator to estimate the hours needed for a temperature increase.
The cheapest heat is the heat you do not lose. Cover the pool between uses and protect it from wind before blaming the heater for the fuel bill.