How much does it cost to run a space heater?
Short answer
A 1,500 watt space heater on high uses 1.5 kWh an hour. At 18 cents per kWh, close to the US average, that’s about 27 cents an hour, $2.16 for an 8-hour day, and about $66 a month.
Work it out for your numbers
Cost per month
$65.70
- Per hour
- $0.27
- Per day
- $2.16
- Energy per day
- 12 kWh
- Per winter
- $262.80 (4 months)
The formula
Watts ÷ 1,000 × hours × your price per kWh. A 1,500 watt heater for 8 hours is 12 kWh, and 12 × $0.18 is $2.16. Your rate is on your electric bill. The US Energy Information Administration put the average residential price at 17.3 cents in 2025 and expects about 18.2 cents in 2026, but many areas pay much more.
Cost by hours a day
| Hours a day | Per day | Per month | Per 4-month winter |
|---|---|---|---|
| 2 | $0.54 | $16.43 | $65.70 |
| 4 | $1.08 | $32.85 | $131.40 |
| 8 | $2.16 | $65.70 | $262.80 |
| 12 | $3.24 | $98.55 | $394.20 |
| 24 | $6.48 | $197.10 | $788.40 |
A 1,500 watt heater at $0.18 per kWh. At 25 cents per kWh, 8 hours a day costs about $91 a month. On the 750 watt low setting, every figure is half.
Why your real bill may be lower
These figures assume the heater runs at full power the whole time. A heater with a thermostat switches off once the room is warm, so in a small, well-insulated room it may only run half the time.
Do some heaters cost less to run?
Not per hour at the same wattage. Every electric resistance heater, whether ceramic, oil-filled or infrared, turns essentially all of its electricity into heat. A 1,500 watt heater of any type uses 1.5 kWh an hour. The type changes how the heat feels, not what it costs. “Energy saving” models save by running at lower wattage or cycling with a thermostat.
Space heater or central heat?
Heating one room you’re in while the rest of the house stays cooler can save money. Heating several rooms with space heaters usually costs more than a gas furnace or heat pump.
Use it safely
- Plug it straight into a wall outlet, not an extension cord or power strip.
- Keep it at least 3 feet from anything that can burn: bedding, curtains, furniture.
- Choose one with tip-over and overheat shutoff, and turn it off when you leave the room or go to sleep.
Common questions
How much does it cost to run a space heater all night?
About $2.16 for 8 hours at full power on high, at 18 cents per kWh. With a thermostat cycling it off, often less.
Does a space heater use a lot of electricity?
On high, 1.5 kWh an hour, which is one of the biggest loads you can plug into a normal outlet. At 8 hours a day, that’s 360 kWh and roughly $66 a month.
Are oil-filled heaters cheaper to run?
Not at the same wattage. They hold heat longer and feel gentler, but 1,500 watts costs the same per hour whatever the type.
Sources
Updated October 29, 2026. Figures are estimates for planning. Check product labels and local codes before you buy or build.