What Does It Cost to Run a Space Heater?
A 1,500 watt space heater used 8 hours a day for a 120 day winter uses 1,440 kWh, which costs about $261 at the US average rate of 18.16 cents per kWh. A heat pump giving the same heat at COP 3 would use a third of that.
Try your own numbers
Last checked 11/10/2026. Sources: U.S. Energy Information Administration: Electric Power Monthly, Table 5.6.A; U.S. Department of Energy: Estimating appliance and home electronic energy use.
Why a plug-in heater costs what it does
A heater turns all the electricity it uses into heat, so 1,500 W is 1.5 kWh for every hour it runs at full power. Eight hours at 18.16 cents per kWh is $2.18 a day, and 120 days is $261. That is the cost if it runs at full power the whole time; a thermostat that cycles it off will cut the figure.
The 18.16 cents is the EIA’s US average residential price for August 2026. Your state’s price may be very different: Louisiana was 12.87 cents and Hawaii 47.18 cents in the same table. Pick your state and the cost updates.
Why 1,500 W? It is the usual limit for a plug-in heater on a standard US 15 A, 120 V circuit. The heat pump column shows what the same heat would cost from an efficient heat pump; the COP is an editable assumption, not a measured figure for any model.
Common questions
Is it cheaper to heat one room with a space heater?
It can be, if you would otherwise heat the whole house. The calculator gives you the running cost of the heater so you can compare it with your whole-house bill.
Does a heater with a thermostat use less?
Yes. Once the room is warm it switches off, so enter the share of the time it runs in the appliance calculator.