How Much Does It Cost to Run a Space Heater?

At full output a 1,500 W heater uses 1.5 kWh per hour. At the 2025 national average of about 17 cents per kWh that is roughly 26 cents an hour, and it ranges from about 18 cents in the cheapest states to over 60 cents in Hawaii. With the thermostat cycling, the real cost per hour of 'on' time is usually 50 to 70 percent of that.

Only partly. The 750 W setting draws half the power, but it runs longer to hold the same room temperature. You save money when the low setting is enough to keep the room comfortable, because the heater spends less time overshooting and the losses through walls and windows are a little lower at a steadier temperature.

It depends on what your central system burns. Against a gas furnace, the space heater is usually the more expensive way to heat a whole house but can be cheaper if you heat one room and turn the furnace down. Against a heat pump, the space heater costs two to three times more per unit of heat. Against electric baseboard or an electric furnace it is the same cost per unit of heat, so the only saving comes from heating fewer rooms.

No. Both convert electricity to heat at 100 percent, so a 1,500 W oil-filled radiator and a 1,500 W ceramic fan heater cost exactly the same per hour of element time. The oil-filled unit feels gentler and keeps radiating after the element shuts off, which can make the thermostat cycle less often, but the total energy to hold a room at a temperature is the same.

About $37 a month at the national average rate. A 1,500 W heater on for 8 hours a day at a 60 percent duty cycle uses 1.5 x 8 x 0.6 = 7.2 kWh a day, or 216 kWh over 30 days, and 216 x $0.173 is about $37. If the element runs nonstop for those 8 hours the figure rises to 360 kWh, about $62.

Most plug-in space heaters use 1,500 W on high and about 750 W on low. 1,500 W is the practical ceiling for a heater on a standard 120 V, 15 A household outlet, which is why almost every model lands on that number regardless of size or style.

About $1.25 for an 8 hour night with the thermostat cycling. That is 1.5 kW x 8 hours x 0.6 duty = 7.2 kWh at 17.3 cents. With no thermostat, or in a cold drafty room where the element never shuts off, it is 12 kWh, about $2.08.

Yes, it is one of the biggest loads you can plug into a wall outlet. At 1,500 W it draws 12.5 A at 120 V, most of a 15 A circuit, and it uses as much electricity in one hour as a 60 W ceiling fan uses in 25 hours.

A power station needs an inverter rated for at least 1,500 W continuous, and even then a 1 kWh battery lasts only about 40 minutes at full output (1,000 Wh divided by 1,500 W, less inverter losses). A generator is more practical: a 2,000 W or larger unit can carry one heater on high, since a resistance heater has no start-up surge.

Shorten the hours the element is on. Use the thermostat instead of the manual high setting, put the heater on a timer, close the door, and block drafts. Every hour of element time you cut saves 1.5 kWh, about 26 cents at the national average rate.