How Much Does a Space Heater Cost to Run?

• Per unit of heat, almost never. A space heater makes the same heat as a 95% gas furnace for 1.7 times the cost in Florida up to 6.0 times in Alaska.^[1][2]
• It saves money when you heat less space. The DOE says a small space heater can cost less "if you only want to heat one room."^[4] That means turning the central heat down for the rest of the house. The DOE says turning the thermostat back 7 to 10°F for 8 hours a day can save up to 10% a year on heating and cooling.^[5]
• A heat pump or mini split beats both on electricity. It moves heat instead of making it. The DOE says heat pumps "easily cut electricity use by 50%" compared with electric resistance heat,^[3] and the mini split below delivers about 2.9 times as much heat per kWh as any space heater.^[10]

Each heater here says in its own listing that it has a thermostat, tip-over and overheat shutoff and a safety listing (UL, ETL or CSA). Our picks are the cheapest of those sold by Amazon.com.^[11]

Quick heat for a small room

Comfort Zone fan heater

A fan heater warms the air near you fast. Good for a desk or office. ETL listed, thermostat, tip-over and overheat shutoff.

$24.48 at Amazon · costs the same $0.27 an hour on high as any 1,500 W heater

Check price on Amazon

Quiet, steady heat for a bedroom

Amazon Basics oil-filled radiator

An oil-filled radiator has no fan, so it is silent, and stays warm after it cycles off. ETL listed, thermostat, tip-over and overheat shutoff.

$70.19 at Amazon · costs the same $0.27 an hour on high as any 1,500 W heater

Check price on Amazon

Need one for a bathroom, a large room or a garage? See our space heater picks for every room. For the safety-checked heaters under $50, see the best space heater under $50.

We checked these against CPSC space heater recalls from 2024 to 2026; recalled models are left out.^[9]

A 1,500 W heater on high. "Times gas" is how many times more the same heat costs than from a 95% gas furnace in that state.^[1][2]

Per hour = 1.5 kWh × the state's average residential price. Gas: 5,118 Btu (1,500 W × 3.412) ÷ 0.95 ÷ 1,037 Btu per cubic foot × the state's residential gas price. * Gas price from 2024, the latest year EIA has for that state.

• Keep it at least 3 feet from drapes, furniture and bedding. Plug it straight into a wall outlet, never an extension cord or power strip.^[8]
• Never leave it on while you sleep, and turn it off when you leave the room.^[8]
• Buy one with a tip-over switch, a thermostat and a safety lab label such as UL.^[4]
• This is why it matters: space heaters and heating stoves cause about 3 in 10 home heating fires but 73% of the deaths from them (2020 to 2024).^[7]
• The CPSC counts about 1,600 fires, 70 deaths and 150 injuries a year from portable heaters (2020 to 2022).^[8]

Cold at night? A heated blanket costs a fraction of a heater to run: heated blanket vs space heater.

How much does it cost to run a 1,500-watt space heater for a month?

At the U.S. average of 18.19 cents per kWh, $65 a month at 8 hours a day, or $196 if it ran nonstop. In Alaska it is $98 at 8 hours a day. A thermostat cycles the heater off once the room is warm, so these full-power numbers are the most it can cost. ^[1]

What is the most energy-efficient space heater?

None. Every plug-in electric heater turns all of its electricity into heat, so they all cost the same per hour at the same wattage. We checked the energy claims on Amazon heater listings. See our page on the most energy-efficient space heater, linked below. ^[3]

Is it cheaper to run a space heater or the furnace?

Per unit of heat, a gas furnace is cheaper in every state but none: a space heater costs 1.7 to 6.0 times as much (Florida to Alaska). A space heater saves money only when you turn the whole-house thermostat down and heat one room. ^[1][2]

Are space heaters safe to leave on overnight?

No. The CPSC says never leave a portable heater on while sleeping, and NFPA says to turn it off when you leave the room or go to bed. Keep it 3 feet from drapes, furniture and bedding, and plug it straight into a wall outlet, not an extension cord or power strip. ^[8][7]

Does a bigger space heater heat a room faster for less?

No. Plug-in space heaters for homes are almost all 1,500 watts on high; all 30 on our list are. So a "large room" heater uses the same power as a small one. A fan or oscillation may spread the heat better, but it costs the same per hour on high. ^[11]

1. 1

   U.S. EIA: Electric Power Monthly, Table 5.6.B, average residential price of electricity by state

   Year-to-Date through July 2026, read October 13, 2026. Cents per kWh.

2. 2

   U.S. EIA: Natural gas prices, residential, by state

   2025 annual average; Connecticut, Maine, Maryland, North Carolina, Rhode Island, South Carolina: latest year EIA has (2024). Dollars per thousand cubic feet.

3. 3

   U.S. DOE Energy Saver: Electric Resistance Heating (archived copy, January 1, 2026)

   "Electric resistance heating is 100% energy efficient in the sense that all the incoming electric energy is converted to heat." Heat pumps "easily cut electricity use by 50%" compared with it.

4. 4

   U.S. DOE Energy Saver: Small Space Heaters (archived copy, March 24, 2026)

   Can be less expensive "if you only want to heat one room"; look for the UL label, a thermostat and a tip-over switch; plug directly into the wall outlet.

5. 5

   U.S. DOE: Home Upgrades (thermostat setback)

   "You can save as much as 10% a year on heating and cooling by simply turning your thermostat back 7°-10°F for 8 hours a day." Read October 13, 2026.

6. 6

   U.S. EIA FAQ: converting natural gas prices to dollars per Btu

   2025 average heat content of delivered natural gas: about 1,037 Btu per cubic foot. 1 kWh = 3,412 Btu (EIA), so 1 W = 3.412 Btu per hour.

7. 7

   NFPA: Heating equipment safety, statistics on heating fires (2020-2024 annual averages)

   Read October 17, 2026. 37,365 home heating equipment fires a year, 417 deaths. "Space heaters and heating stoves ... accounting for nearly a third (30%) of the fires, but over seven out of ten deaths (73%) and seven out of ten (70%) of the injuries in home fires caused by heating equipment." NFPA safety card: "Keep space heaters 3 feet away."

8. 8

   U.S. CPSC news release, January 23, 2026: Keep warm and safe this winter (generators, furnaces and space heaters)

   Read October 17, 2026. Portable heaters, including electric space heaters: an average of 1,600 fires, 70 deaths and 150 injuries a year (2020 to 2022). 3 feet from drapes, furniture and bedding; plug directly into a wall outlet, never an extension cord or power strip; "Turn off heaters when sleeping."

9. 9

   U.S. CPSC recalls database: electric portable heaters recalled 2024-2026

   Vornado SRTH (June 4, 2026), Vornado VH2 (Jan 16, 2025), Govee/GoveeLife H7130-H7135 (Nov 7, 2024), Atomi smart heaters (July 11, 2024), Merkury MI-DHC02 (June 11, 2026), Meijer Konwin BHN2133 (Mar 13, 2025).

10. 10

    AHRI Directory: certified rating, reference 218067069 (Klimaire DIY 12,000 BTU (230 V))

    HSPF2 10. Seasonal heat out per unit of electricity = HSPF2 ÷ 3.412 = 2.9.

11. 11

    Amazon.com listings (features from each listing; price and seller from the buy box)

    Buy boxes read November 11, 2026. Prices change; the button shows today's.

Related: oil-filled vs ceramic heater: which is cheaper to run · electric fireplace inserts by opening size · most energy-efficient space heater · heated blanket vs space heater · keep pipes from freezing · why heater room-size claims don’t add up · heat pump vs furnace · DIY mini splits · smart thermostats · furnace filters by size · small heaters for under an office desk