How Much Does It Cost to Run a Garage Heater?
How much does it cost to run a garage heater? For the default 24,500 BTU/hr electric load, 17.30¢/kWh and 65% runtime give $0.81 per hour of garage use, or $86.51 per month at five hours a day, five days a week. Change the inputs for your garage.
This is a planning estimate. Your actual bill depends on weather, insulation, thermostat settings, ventilation, and local utility rates.
Cheapest fuel for your garage
At the reference prices below, natural gas delivers heat for the least money, about $18.50 per million BTU. Electric resistance heat costs the most to run but the least to install, so the cheapest choice overall depends on how many hours you heat. The cheapest way to heat a garage ranks every option for your size and schedule.
What does a 1,500, 4,000, or 5,000 W heater cost to run?
These electric-resistance examples use 17.30¢/kWh, four hours a day and seven days a week. Each month is 30 days. The last column assumes the thermostat keeps the heater on about 65% of the time, which is what “duty cycle” means: the share of your garage time the heater is actually running.
| Heater | Hour at full power | Month, full power | Month, 65% of the time |
|---|---|---|---|
| 1,500 W | $0.26 | $31.14 | $20.24 |
| 4,000 W | $0.69 | $83.04 | $53.98 |
| 5,000 W | $0.86 | $103.80 | $67.47 |
| 7,500 W | $1.30 | $155.70 | $101.20 |
Propane vs. electric vs. natural gas garage heating
Compare the cost of equal delivered heat before comparing bills. The following values assume 100% conversion for electric resistance and 80% for the two combustion fuels. They use dated reference prices from different periods, listed below.
| Fuel | Reference rate | Per million delivered BTU | Guide |
|---|---|---|---|
| Natural gas | $1.48/therm | $18.50 | Natural gas heaters |
| Propane | $2.553/gal | $34.90 | Propane heaters |
| Electric resistance | $0.1730/kWh | $50.70 | Electric heaters |
A portable fan heater and an electric infrared heater of equal wattage use the same electricity while running at full power. Infrared can reduce the area you need to heat, but it does not turn one kWh into a different amount of resistance heat. A heat pump can deliver more heat per kWh; compare its cold-weather performance separately. Wood cost depends on moisture, stove efficiency, purchased versus self-supplied fuel, and local prices, so no universal wood-heating monthly figure is assumed.
How the math works
Electric hourly cost equals delivered BTU/hr divided by 3,412, multiplied by dollars per kWh and duty cycle. Gas and propane first divide output by 0.80 to estimate input. Divide that input by 100,000 BTU per therm for gas, or 91,452 BTU per gallon for propane, then multiply by the fuel price and duty cycle.
Monthly cost equals hourly cost times hours per day, times 30 days, times the share of the week you use the garage (days per week divided by seven). Seasonal cost multiplies the monthly result by the selected months. These scheduled months are not a weather forecast. All calculator cards and state-rate examples use this same 30-day month.
A worked two-car garage example
The default 24,500 BTU/hr electric load costs $1.24 per hour of uninterrupted runtime, or $0.81 per hour of garage use at a 65% duty cycle. Five hours a day, five days a week gives $86.51 per 30-day month and $346.05 over four months.
The duty presets are illustrative. A heater can run continuously during warm-up or severe weather; a well-insulated space does not guarantee 50% runtime. The estimate excludes installation, fixed monthly charges not caused by heating, and unusual tariff adjustments. One-time work is covered separately under garage heater installation cost.
Three practical ways to cut garage heating cost
Start with insulation and door seals. Reduce drafts around the bottom and sides of overhead doors and address uninsulated surfaces. The saving depends on the original enclosure; a universal percentage or payback period would be misleading.
Lower the target temperature when your work allows it. Compare two setpoints in the garage heater size calculator while holding dimensions and outdoor temperature constant. The methodology explains the relationship between temperature rise and estimated heat loss.
Heat the occupied work area for short projects instead of holding every bay at working temperature. Select suitable equipment and clearances for that zone. A tall workshop also benefits from checking distribution and stratification before increasing capacity; the shop heater BTU calculator uses its real ceiling height.
Use the state electricity table for a dated starting price, including a detailed Texas garage-heating example. Your own bill remains the better input.
Price sources and dates
Default electricity is 17.30¢/kWh, the EIA U.S. residential 2025 annual average. Annual defaults avoid treating one summer month as a typical heating price. State electricity pages separately show dated monthly observations; selecting one deliberately replaces this annual default. Your own bill is the better input.
Natural gas uses the EIA U.S. residential 2025 annual average, $15.34 per thousand cubic feet. The same year's national heat content is 1,036 BTU/cubic foot, so $15.34 ÷ 10.36 ≈ $1.48/therm. This remains an approximate national conversion, not your utility's billed heat content.
Default propane is $2.553/gallon, rounded from the arithmetic mean of 26 EIA U.S. residential weekly observations from October 6, 2025 through March 30, 2026, excluding taxes. It is our time-series average of published survey prices, not an EIA sales-volume-weighted seasonal average. Survey geography is limited; annual electric/gas and seasonal propane references do not cover identical periods.
- EIA annual residential electricity price
- EIA annual residential natural gas prices and same-year heat content
- EIA weekly residential propane history
Reviewed October 1, 2026. These are budgeting references, not live offers or a winter forecast. Average electricity and gas prices can reflect fixed charges; the extra cost of heating may differ. Enter your local energy charges and account separately for any new fixed service fees. Canadian locations still use USD references, not Canadian tariffs.
Garage heater cost questions
How much does it cost to run a garage heater per hour?
For the default 24,500 BTU/hr electric load, a 17.30¢/kWh rate and 65% duty cycle give about $0.81 per hour of garage use. At full power the same load costs $1.24 per hour of runtime. Your local price and thermostat cycling change both estimates.
How much does it cost to run a 1,500 watt garage heater?
At the electricity reference rate, 1.5 kW multiplied by $0.1730/kWh is $0.26 per hour while the element runs. Thermostat cycling lowers average hourly energy use. Whether 1,500 W heats the whole garage depends on its heat loss.
Is propane or electric cheaper for heating a garage?
For equal delivered heat at the dated reference prices, natural gas is about $18.50 per million BTU, propane $34.90, and electric resistance $50.70. Gas and propane assume 80% efficiency. These prices use different observation dates; local quotes can change the order.
Why does the calculator multiply by a duty cycle?
Duty cycle is the share of scheduled time that the heater actually runs. The 50%, 65%, and 80% options are scenarios, not measured values for every garage. Choose 100% for uninterrupted runtime. Warm-up, cold weather, and open doors can push runtime toward 100%; a satisfied thermostat can reduce it substantially.
How do I use a state electricity rate?
Choose a state in the form or follow a state-rate link. The field uses dollars per kWh, so 15.88 cents becomes $0.1588. State averages are dated references, not your utility tariff. Replace the number with the relevant rate from your own bill; fixed charges and time-of-use pricing may need separate treatment.