How Much Does It Cost to Run a Space Heater?
Every plug-in heater turns electricity into heat at the same efficiency, so the only numbers that matter are its wattage, the hours it runs and what you pay per kilowatt-hour.
Quick answer
A typical space heater draws up to 1,500 watts on high, which uses 1.5 kWh per hour. At the U.S. average residential rate of 18.31 cents per kWh (July 2026), that is about 27 cents an hour, $2.20 for an 8-hour day and roughly $67 a month. On the low setting (around 750 watts) the cost is half that.
- Difficulty
- Easy DIY
- High setting
- 1,500 W = about 27¢ per hour
- 8 hours a day
- About $67 a month
- Low setting
- About 750 W, half the cost
- Rate used
- 18.31¢/kWh, U.S. average (EIA)
On this page
Space heaters are simple: electricity runs through a resistance element and becomes heat. Ceramic, oil-filled, infrared and fan-forced models all turn about 100 percent of the power they draw into heat. A 1,500-watt heater of any type puts out the same amount of heat and costs the same to run per hour on its highest setting.
Most portable heaters top out at 1,500 watts because that is about the most a standard 120-volt household circuit can safely supply continuously. Many have a low setting around 750 to 900 watts.
The calculation
Cost per hour = watts ÷ 1,000 × your rate per kWh
1,500 W ÷ 1,000 = 1.5 kWh per hour. At 18.31¢ per kWh, that is 1.5 × $0.1831 = $0.27 per hour.
Cost by electricity rate
Electricity prices vary widely by state, so here is the cost of a 1,500-watt heater at four common rates. The middle column is the U.S. average reported by the Energy Information Administration for July 2026.
| Use | At 12¢/kWh | At 18.31¢/kWh | At 25¢/kWh | At 35¢/kWh |
|---|---|---|---|---|
| 1 hour | 18¢ | 27¢ | 38¢ | 53¢ |
| 8 hours | $1.44 | $2.20 | $3.00 | $4.20 |
| Month, 4 hours a day | $21.89 | $33.40 | $45.60 | $63.84 |
| Month, 8 hours a day | $43.78 | $66.79 | $91.20 | $127.68 |
| Month, 24 hours a day | $131.33 | $200.38 | $273.60 | $383.04 |
Months are calculated as 30.4 days. The 24-hour row is the worst case; a heater with a thermostat cycles off once the room is warm, so real costs are often lower.
To use your exact rate and settings, try the appliance energy cost calculator. It works in dollars, pounds, euros and Canadian and Australian dollars.
Does a space heater save money?
It depends on what it replaces.
- Heating one room while the rest of the house stays cool: often yes. Turning the central thermostat down several degrees and warming only the room you are in can cost less than heating the whole house, especially overnight in a bedroom.
- Heating the whole house with space heaters: usually no. Electric resistance heat delivers 3,412 BTU per kWh. A heat pump can move two to four times as much heat for the same electricity, and gas furnaces are usually cheaper per unit of heat in most of the U.S.
- Making up for a drafty room: sealing gaps around windows and doors may solve the problem more cheaply than running a heater all winter.
Use it safely
According to the National Fire Protection Association, space heaters and heating stoves accounted for about 30 percent of home heating equipment fires but 73 percent of the deaths in 2020 to 2024. The leading factor in heating fire deaths was equipment placed too close to things that can burn.
- Keep a three-foot clear zone.
Nothing that can burn, such as bedding, curtains, furniture or paper, within three feet of the heater, as the NFPA recommends.
- Plug it directly into a wall outlet.
Not an extension cord or power strip. If the plug or outlet feels hot, stop using it.
- Choose a heater with tip-over and overheat shutoff
and a certification mark from a recognized testing lab such as UL, ETL or CSA.
- Turn it off when you leave the room or go to sleep.
Use a heater with a thermostat and timer if you want it to run unattended for short periods.
- Test your smoke alarms.
Heating season is a good time to check them. See why a smoke alarm chirps.
Frequently asked questions
Do space heaters use a lot of electricity?
Compared with most household devices, yes. At 1,500 watts, a heater draws as much as a hair dryer or microwave, but it runs for hours instead of minutes. Running one 8 hours a day uses about 365 kWh a month.
Are oil-filled or ceramic space heaters cheaper to run?
Not per hour at the same wattage. All electric resistance heaters convert essentially 100 percent of their electricity into heat. Oil-filled radiators hold heat and release it gently, which can feel more even, but 1,500 watts costs the same in any design.
Is it cheaper to run a space heater than central heat?
It can be if you heat one room and turn the central thermostat down for the rest of the house. Heating a whole home with several space heaters usually costs more than a gas furnace or heat pump.
Can I plug a space heater into an extension cord?
Safety agencies advise plugging space heaters directly into a wall outlet. Extension cords and power strips can overheat under a heater’s sustained load.
Sources
- Electric Power Monthly, Table 5.6.A: Average Price of Electricity to Ultimate Customers U.S. Energy Information Administration
- Portable Heaters U.S. Department of Energy, Energy Saver (archived copy, 2025)
- Home Heating Fires National Fire Protection Association
- Heating Safety National Fire Protection Association
First published October 6, 2026. Last reviewed October 6, 2026. Spot an error? Tell us and we will check it against the source.