How Much Does It Cost to Run a Space Heater? Costs by State and City

A 1,500-watt space heater on high uses 1.5 kilowatt-hours of electricity an hour, which costs about 27¢ at the 2026 US average price, $2.18 for an 8-hour day and $65 for a month of 8-hour days. By state, the same hour costs 19¢ in North Dakota and 69¢ in Hawaii.

Below: the formula, costs by state and city, and what the same heat costs from a furnace or heat pump, priced as in our heat pump vs. furnace guide.

The formula: watts × hours × your price

Ceramic, oil-filled, quartz or infrared, every electric space heater is resistance heat, which the U.S. Department of Energy calls 100% efficient because

all the incoming electric energy is converted to heat.

So cost depends only on watts and hours: watts ÷ 1,000 × hours = kWh, and kWh × your price = dollars. Our state averages come from the Energy Information Administration’s Electric Power Monthly, Table 5.6.B, January–July 2026, the same prices behind our hot tub running costs.¹

A heater with a thermostat draws full power only while its element is on, so it costs less than the table once the room is warm.

What a space heater costs in 20 US cities

Table 2 prices one 1,500 W heater on high in the 20 cities of our heat pump vs. furnace estimates, at each state’s average rate.¹ A month of 8-hour days runs from $44 in Fargo to $120 in Sacramento; Boston and New York, at about 30¢ per kWh, cost more than twice what Fargo or Omaha do.

Space heater vs. furnace or heat pump: the price of the same heat

One kWh gives 3,412 Btu,¹⁰ so we can price 100,000 Btu from each source. Against a 95% efficient gas furnace at each state’s 2025 residential gas price,² space heater heat costs 2.2 times as much in Atlanta and 5.7 times as much in Detroit. Against a heat pump with a seasonal COP of 2.4–3.1, it costs 2.4–3.1 times as much. Baseboards and electric furnaces are resistance heat too; DOE adds that electric furnaces cost more to run than other resistance systems because of duct heat losses.⁴

That ratio equals the break-even COP in our furnace comparison, since it compares the same two prices. It also shows why space heaters can’t replace central heat: that guide’s example home (500 Btu an hour per °F of indoor-outdoor difference) would need 3.8 heaters running nonstop through a normal Chicago January (26°F average, NOAA 1991–2020).³ Heated all winter that way, it would cost about $4,068 a year against $825 with gas.

When a space heater actually saves money

A space heater is economical only if you use it judiciously.

Zone heating means turning the thermostat down and warming only the room you’re in. The heater’s heat stays in the house and replaces some furnace heat, but at 4.9 times the price in Chicago. So each kWh it uses must save about 16,800 Btu of furnace heat: 3,412 from the heater itself, about 13,400 from the cooler rest of the house.

By city, the gas-heat break-even runs from 313 W in Detroit to 1,247 W in Atlanta; with a COP 3.1 heat pump it is about 700 W everywhere. With baseboard or electric furnace heat, any setback elsewhere saves money, because both heats cost the same per Btu. These are upper limits, since the heated room stays warm. Our winter thermostat guide estimates setback savings by city; heat pump owners should first check how backup heat behaves in the cold, and rooms you let cool must stay above our pipe-freezing thresholds.

Does the type of heater change the cost?

Not per kWh: all types turn electricity into heat one for one. DOE recommends a thermostatically controlled heater “because they avoid the energy waste of overheating a room,” sized for the room, and calls radiant heaters more efficient when you stay in their line of sight for a few hours.⁵ Many heaters Consumer Reports tested claim to heat only about 150 to 200 square feet.⁹ For outages, our generator size calculator counts a space heater as a 750–1,500 W load.

Space heater safety: what CPSC and NFPA count

Portable heaters, including electric space heaters, were involved in an average of 1,600 fires, 70 deaths and 150 injuries a year in 2020–2022, CPSC estimates.⁶ In NFPA’s 2020–2024 averages, space heaters and heating stoves caused 30% of home heating equipment fires but 73% of the deaths, and 46% of those fires came in December through February.⁷ NFPA’s tip sheet wants a testing-lab seal, overheat and tip-over protection, 3 feet from anything that can burn, including people, and the heater off and unplugged when you leave the room or go to bed.⁸ Check it against CPSC recalls too.⁶

Plug the heater directly into the wall outlet. Never use an extension cord.

Your next step

Multiply your heater’s label watts by your hours and your bill’s price per kWh. Heating several rooms this way? Check our break-even COP method first.