How much does it cost to run a space heater?
Short answer: A space heater drawing 1,500 watts costs about $0.27 per hour at the U.S. average residential price of 18.31¢ per kWh. Used 8 hours a day, 30 days a month, that is about $65.92 per month and $790.99 per year. In Louisiana, the cheapest state, the same use costs $45.79 a month; in Hawaii, the most expensive, $172.80.
Space heater cost calculator
Hours the heater is actually producing heat. A thermostat model in a small, closed room may run only half the time it is switched on.
Energy used: 360.0 kWh per month. Default price is the U.S. residential average; pick your state or type the price from your own bill.
Almost every plug-in space heater sold in the U.S. tops out at 1,500 watts, because that is the most a standard 15-amp household outlet can safely supply. That makes the math unusually predictable: on high, a space heater uses 1.5 kilowatt-hours for every hour it runs.
Cost by size and setting
Costs below use the U.S. average price and 8 hours a day, 30 days a month.
| Type | Power | Per hour | Per month |
|---|---|---|---|
| Small personal heater | 750 W | $0.14 | $32.96 |
| Standard heater on low | 1,000 W | $0.18 | $43.94 |
| Standard heater on high | 1,500 W | $0.27 | $65.92 |
What actually drives the cost
Wattage and run time are the only two things that matter. The style of heater does not. An oil-filled radiator, a ceramic tower and a $20 fan heater that are all rated at 1,500 watts turn exactly the same amount of electricity into exactly the same amount of heat. Marketing claims about one type being "more efficient" are about comfort and how the heat is delivered, not about the bill.
What does change the bill is how often the heating element is on. A heater with a real thermostat cycles off once the room reaches temperature, so eight hours of being switched on may be only four or five hours of drawing power. A heater with no thermostat, or one fighting a drafty room, runs flat out the whole time.
Is a space heater cheaper than central heat?
Only when you use it to heat less space. Warming one occupied room and turning the whole-house thermostat down several degrees can save money. Running three space heaters to warm a whole home with electric resistance heat almost never does, and it is usually far more expensive than a gas furnace or a heat pump doing the same job.
How to lower the cost
- Use the low setting once the room is warm: 750 watts costs half as much per hour as 1,500.
- Close the door. A heater in an open-plan space never reaches its set point and never cycles off.
- Pick a model with a thermostat and a timer so it does not run all night at full power.
- Seal the obvious drafts first. Weatherstripping is a one-time cost; the heater is a monthly one.
Cost to run a space heater in every state
Based on 1,500 watts for 8 hours a day, 30 days a month, at each state's average residential electricity price for July 2026.
| State | Price per kWh | Per hour | Per month | Per year |
|---|---|---|---|---|
| Alabama | 16.40¢ | $0.25 | $59.04 | $708.48 |
| Alaska | 28.83¢ | $0.43 | $103.79 | $1,245 |
| Arizona | 15.38¢ | $0.23 | $55.37 | $664.42 |
| Arkansas | 14.33¢ | $0.21 | $51.59 | $619.06 |
| California | 33.61¢ | $0.50 | $121.00 | $1,452 |
| Colorado | 17.00¢ | $0.26 | $61.20 | $734.40 |
| Connecticut | 24.16¢ | $0.36 | $86.98 | $1,044 |
| Delaware | 18.48¢ | $0.28 | $66.53 | $798.34 |
| District of Columbia | 25.21¢ | $0.38 | $90.76 | $1,089 |
| Florida | 15.03¢ | $0.23 | $54.11 | $649.30 |
| Georgia | 16.27¢ | $0.24 | $58.57 | $702.86 |
| Hawaii | 48.00¢ | $0.72 | $172.80 | $2,074 |
| Idaho | 13.73¢ | $0.21 | $49.43 | $593.14 |
| Illinois | 19.22¢ | $0.29 | $69.19 | $830.30 |
| Indiana | 16.73¢ | $0.25 | $60.23 | $722.74 |
| Iowa | 15.99¢ | $0.24 | $57.56 | $690.77 |
| Kansas | 15.27¢ | $0.23 | $54.97 | $659.66 |
| Kentucky | 13.81¢ | $0.21 | $49.72 | $596.59 |
| Louisiana | 12.72¢ | $0.19 | $45.79 | $549.50 |
| Maine | 32.41¢ | $0.49 | $116.68 | $1,400 |
| Maryland | 21.41¢ | $0.32 | $77.08 | $924.91 |
| Massachusetts | 30.49¢ | $0.46 | $109.76 | $1,317 |
| Michigan | 23.05¢ | $0.35 | $82.98 | $995.76 |
| Minnesota | 17.45¢ | $0.26 | $62.82 | $753.84 |
| Mississippi | 14.54¢ | $0.22 | $52.34 | $628.13 |
| Missouri | 16.09¢ | $0.24 | $57.92 | $695.09 |
| Montana | 14.99¢ | $0.22 | $53.96 | $647.57 |
| Nebraska | 13.78¢ | $0.21 | $49.61 | $595.30 |
| Nevada | 12.77¢ | $0.19 | $45.97 | $551.66 |
| New Hampshire | 26.60¢ | $0.40 | $95.76 | $1,149 |
| New Jersey | 25.19¢ | $0.38 | $90.68 | $1,088 |
| New Mexico | 16.09¢ | $0.24 | $57.92 | $695.09 |
| New York | 29.90¢ | $0.45 | $107.64 | $1,292 |
| North Carolina | 15.16¢ | $0.23 | $54.58 | $654.91 |
| North Dakota | 13.41¢ | $0.20 | $48.28 | $579.31 |
| Ohio | 19.45¢ | $0.29 | $70.02 | $840.24 |
| Oklahoma | 14.35¢ | $0.22 | $51.66 | $619.92 |
| Oregon | 15.97¢ | $0.24 | $57.49 | $689.90 |
| Pennsylvania | 21.72¢ | $0.33 | $78.19 | $938.30 |
| Rhode Island | 28.29¢ | $0.42 | $101.84 | $1,222 |
| South Carolina | 15.47¢ | $0.23 | $55.69 | $668.30 |
| South Dakota | 15.37¢ | $0.23 | $55.33 | $663.98 |
| Tennessee | 13.71¢ | $0.21 | $49.36 | $592.27 |
| Texas | 15.88¢ | $0.24 | $57.17 | $686.02 |
| Utah | 13.12¢ | $0.20 | $47.23 | $566.78 |
| Vermont | 23.75¢ | $0.36 | $85.50 | $1,026 |
| Virginia | 17.55¢ | $0.26 | $63.18 | $758.16 |
| Washington | 14.71¢ | $0.22 | $52.96 | $635.47 |
| West Virginia | 15.78¢ | $0.24 | $56.81 | $681.70 |
| Wisconsin | 19.06¢ | $0.29 | $68.62 | $823.39 |
| Wyoming | 14.36¢ | $0.22 | $51.70 | $620.35 |
Frequently asked questions
How much does it cost to run a 1,500-watt space heater for 24 hours?
A 1,500-watt heater running non-stop uses 36 kWh in 24 hours. At the U.S. average residential price that is about $6.59. In practice a thermostat-controlled heater will cycle off and cost less.
Do oil-filled heaters use less electricity?
No. An oil-filled radiator rated at 1,500 watts uses the same power as any other 1,500-watt heater while its element is on. It keeps radiating heat after it cycles off, which feels steadier, but the energy in equals the heat out for every electric resistance heater.
Can a space heater raise my bill by $100 a month?
Yes, easily, in a high-price state. One heater on high for 8 hours a day uses about 360 kWh a month. Check the state table above to see what that costs where you live.