EN/US · unofficial estimator
How much does a gas fireplace cost to run?
GasFireCost turns fireplace BTU/hr, hours of use, and your $/therm or $/gallon into live hourly, daily, monthly, and seasonal cost. Fuel math only — no OEM or utility affiliation.
Running cost calculator
US default $1.47/therm. Using default.
Default 720 hours (hours/day × 180 days).
Per hour
$0.59
Main burner
Per day
$2.35
4 h on
Per month
$70.56
Per season
$423.36
720 h
Fuel use: 0.4 therms/hour of burner time (40,000 BTU/hr after assumptions).
GasFireCost is unofficial. It estimates fuel cost from BTU ratings and the rates you enter. It does not include taxes, utility customer charges, tank rental, or installation. No affiliation with OEMs or utilities. Verify rates with your utility or propane supplier. See methodology.
- Month
- $70.56
- Season
- $423.36
What the numbers mean
Natural gas is billed in therms (100,000 BTU). Propane is billed in gallons (91,500 BTU in this calculator). Cost per hour is fuel burned by the main burner times your rate. Month and season scale that by the hours you enter. A standing pilot is optional extra fuel.
The 75% efficiency toggle is an assumption for vented units: if you treat the BTU figure as heat to the room, fuel input is BTU ÷ efficiency. If your rating is already fuel input, turn the derate off.
Frequently asked questions
How much does a gas fireplace cost per hour?
With the site’s US defaults (30,000 BTU/hr, 75% efficiency assumption, $1.47/therm), a natural gas fireplace is about $0.59 per hour. The same unit on propane at $2.67/gallon is about $1.17 per hour. Your bill depends on nameplate BTU, local rates, and hours used.
What does a gas fireplace cost per month?
At 4 hours per day for 30 days, the default natural gas example is about $71 per month, or about $140 on propane. Cut hours in half and the main-burner cost halves. A 24-hour pilot adds a smaller, steadier monthly amount.
How much does a standing pilot light cost?
A 600–1,000 BTU/hr pilot running 24 hours uses about 0.14–0.24 therms per day on natural gas, or roughly $6–$11 per month at $1.47/therm before the main burner. Enable “pilot light on” in the calculator and set BTU/hr from your manual.
Is GasFireCost affiliated with a utility or fireplace brand?
No. GasFireCost is an unofficial estimator. It is not a utility, OEM, dealer, or billing tool. Figures are planning estimates. Confirm rates, therm factors, and appliance ratings with your utility, propane supplier, and the fireplace manual.