How-To space heater electricity cost energy bill heating kWh

How Much Does It Cost to Run a Space Heater? Per Hour, Day and Month (2026 Rates)

By ClickSolveTools Editorial TeamUpdated 9 min read

A 1,500 watt space heater costs about 27 cents an hour to run at the US average residential electricity price of 18.16 cents per kilowatt-hour (kWh), the August 2026 figure from the U.S. Energy Information Administration (EIA). That is $2.18 for eight hours and $65.38 for a month at eight hours a day, if the heater runs flat out. A 750 watt heater costs half as much: about 14 cents an hour and $32.69 a month.

The formula works for any heater: watts ÷ 1,000 × hours × your rate per kWh. Your real bill is usually lower, because a thermostat switches the element off once the room is warm. To run your own wattage, hours and rate, use the Electricity Cost Calculator.

Watts and Kilowatt-Hours in Plain Words

Watts measure how fast a device uses electricity, like speed on a car. A kilowatt-hour is how much it used, like miles driven: one kilowatt (1,000 watts) running for one hour, the unit your utility bills, according to EIA. A 1,500 W heater uses 1.5 kWh for every hour it is on. If you need to switch between watts, kilowatts and BTU per hour, the Power Converter does it, and the Energy Converter handles Wh, kWh and BTU.

cost per hour = watts ÷ 1,000 × rate per kWh 1,500 W: 1.5 kWh × $0.1816 = $0.2724, about 27 cents an hour 8 hours: 12 kWh × $0.1816 = $2.18

Space Heater Cost at the US Average Rate

These figures assume the heater draws its full rated power the whole time, which is the most you can pay at this rate:

Heater Per hour 8 hours 8 h a day, 30 days 24 h a day, 30 days
750 W (low setting) 14 cents (0.75 kWh) $1.09 (6 kWh) $32.69 (180 kWh) $98.06 (540 kWh)
1,500 W (high setting) 27 cents (1.5 kWh) $2.18 (12 kWh) $65.38 (360 kWh) $196.13 (1,080 kWh)

For scale, EIA's FAQ puts the average US home at 899 kWh a month (2022 data), so 360 kWh from one heater is about 40% on top of a typical home's use. The August 2026 price is preliminary and 3.4% above August 2025 (17.57 cents); our guide to what inflation is and how it affects your money covers the bigger picture.

Space Heater Cost by State

Rates differ a lot by state. These are EIA's August 2026 residential averages for the lowest state (Nevada), the highest (Hawaii) and five large states.

State Rate per kWh 1,500 W, per hour 1,500 W, 8 h a day, 30 days 750 W, 8 h a day, 30 days
Nevada (lowest) 12.72 cents 19.1 cents $45.79 $22.90
Florida 14.99 cents 22.5 cents $53.96 $26.98
Texas 15.91 cents 23.9 cents $57.28 $28.64
US average 18.16 cents 27.2 cents $65.38 $32.69
Illinois 19.32 cents 29.0 cents $69.55 $34.78
New York 28.65 cents 43.0 cents $103.14 $51.57
California 29.75 cents 44.6 cents $107.10 $53.55
Hawaii (highest) 47.18 cents 70.8 cents $169.85 $84.92

The same heater costs 3.7 times as much to run in Hawaii as in Nevada. These are statewide averages, so your utility may charge more or less. EIA's average is total revenue divided by total kWh sold, and that revenue includes customer charges, surcharges and fees, so it is an all-in average. Check the rate on your own bill (see below).

Why Your Real Cost Is Usually Lower

A thermostat-controlled heater does not draw its full wattage all the time. It switches the element off when the room reaches the set temperature and back on when it cools, so if it runs half the time you pay for half the kWh. For a 1,500 W heater used 8 hours a day for 30 days at the US average rate:

Element is on kWh a month Cost a month
100% of the time 360 $65.38
75% of the time 270 $49.03
50% of the time 180 $32.69
25% of the time 90 $16.34

No official figure says how often a typical heater cycles, since it depends on room size, insulation, outdoor temperature and the set point, so measure it. A plug-in electricity usage monitor reads watts and total kWh for any 120 volt device, and the Department of Energy says they cost around $25 to $50. Check that the rating on the monitor's label covers the heater's wattage, plug the monitor into the wall and the heater into the monitor, and run the heater for an evening while you are in the room. Then multiply the kWh it shows by your rate and plug the heater straight back into the wall. Do not leave it running while you sleep (see the safety rules below).

Heater type does not change the heat you get per kWh

Ceramic, oil-filled, fan and infrared heaters are all electric resistance heaters, and the Department of Energy says all the incoming electric energy is converted to heat, so two heaters with the same wattage cost the same per hour at full power. DOE's small space heater guidance says oil-filled models store some heat so they can cycle less, and radiant heaters are more efficient when you sit in their line of sight for only a few hours, because they warm you directly. An "eco mode" saves money only by running the element less.

Space Heater vs. Central Heat

EIA lists 1 kWh as 3,412 BTU, 1 therm as 100,000 BTU and 1 cubic foot of natural gas as 1,036 BTU. So a 1,500 W heater makes 5,118 BTU an hour, and a therm of resistance heat takes 29.3 kWh. EIA's US residential gas price was $14.09, $13.96 and $14.95 per thousand cubic feet for December 2025 to February 2026, averaging $14.33, or $1.38 per therm of gas. We assumed the furnace efficiency, so the table shows 80% and 95%:

Heat source Cost of 100,000 BTU of heat Cost of one hour of 5,118 BTU
Electric space heater (resistance) $5.32 27.2 cents
Heat pump (65% less electricity than resistance) $1.86 9.5 cents
Natural gas furnace, 80% efficient $1.73 8.9 cents
Natural gas furnace, 95% efficient $1.46 7.5 cents

The heat pump row uses DOE's statement that a modern heat pump can cut heating electricity use by about 65% compared with resistance heating, which is about 2.9 units of heat per unit of electricity. Per BTU, resistance heat costs about 3.1 to 3.7 times what gas heat does at these prices. Pricing electricity at last winter's rate instead (17.40 cents, the December 2025 to February 2026 average in EIA's monthly price table) narrows the gap only slightly, to about 2.9 to 3.5 times.

A space heater can still make sense. DOE says small space heaters can cost less to use when you only need to heat one room, and that zone heating can produce energy savings of more than 20% compared with heating the whole house. The catch is the turn-down: for every BTU the heater makes, turning down the rest of the house has to save your furnace about 3.7 BTU of output (95% furnace) or 3.1 BTU (80% furnace) for your combined gas and electric bills to come out ahead. If your central heat is also electric resistance, the cost per BTU is the same, so heating one room always costs less than heating them all.

What Size Space Heater Do You Need?

A common rule of thumb is about 10 watts per square foot, which puts a 1,500 W heater at roughly 150 square feet. It is a rule of thumb, not a standard, since ceiling height, insulation, windows and outdoor temperature all move it. DOE advises picking the proper size, avoiding oversized heaters and using the sizing table that comes with the unit. Our BTU Calculator sizes room air conditioners only, so it will not give you a heater size. If a dial or thermostat uses the other temperature scale, the Temperature Converter translates it.

What Other Appliances Cost to Run

Here is a 1,500 W heater next to other loads, priced per hour of running at 18.16 cents per kWh. The wattages are typical label values (the same presets as our calculator). Your label wins, since DOE notes the wattage printed on an appliance is its maximum draw.

Appliance Typical watts Cost per hour
Level 2 EV charger (30 amps at 240 volts) 7,200 W $1.31
Electric clothes dryer 5,000 W 90.8 cents
Electric water heater (element on) 4,500 W 81.7 cents
Electric oven 2,400 W 43.6 cents
Space heater (high) 1,500 W 27.2 cents
Window air conditioner 1,200 W 21.8 cents
Desktop PC 200 W 3.6 cents
55 inch LED TV 100 W 1.8 cents

The charger row assumes a charger that draws 30 amps, since Level 2 home charging runs on 240 volts and 30 × 240 is 7,200. Put any of these through the Electricity Cost Calculator to see a month of real use.

Find Your Real Electricity Rate

The state averages are a starting point. On your bill, add up the charges that scale with usage, both supply (the energy itself) and delivery, then divide by the kWh used. Leave out flat monthly fees, since running a heater does not change them. On a time-of-use plan, price the heater at the rate for the hours it runs, and on a tiered plan use the rate of your tier.

Space Heater Safety

These rules come from the U.S. Consumer Product Safety Commission (CPSC), the National Fire Protection Association (NFPA) and DOE:

Five Ways to Cut the Bill

  1. Heat only the room you use and turn the central thermostat down, since the heater only pays off if the rest of the house uses less.
  2. Use the thermostat so the heater cycles instead of running constantly.
  3. Go radiant for short stays: if you will sit in front of the heater for only a few hours, a radiant model warms you directly instead of the whole room.
  4. Keep the heat in: close the door and block drafts at the door and windows.
  5. Check your rate plan: if you have a time-of-use plan, shift heater use to the cheaper hours.

Frequently Asked Questions

Is it cheaper to run a space heater than central heat?

Not per unit of heat, usually. At 18.16 cents per kWh, electric resistance heat costs about $5.32 per 100,000 BTU. Gas heat costs about $1.46 to $1.73 for the same amount from a 95% to 80% efficient furnace, at the winter gas prices EIA reported for December 2025 to February 2026. A space heater can still lower your total bill if it lets you turn the central thermostat down while you heat only the room you are using.

How much does it cost to run a space heater all night?

For 8 hours, a 1,500 W heater uses 12 kWh and costs about $2.18 at the US average rate if it runs the whole time. A thermostat that keeps it on half the time brings that to about $1.09. The Consumer Product Safety Commission says never to leave portable heaters on while sleeping, so heat the room before bed and switch the heater off.

Do energy-saving space heaters use less electricity?

Only by running less. The Department of Energy says electric resistance heating turns all the incoming electric energy into heat, so a ceramic, oil-filled, fan or infrared heater of the same wattage uses the same electricity per hour at full power. Savings come from a thermostat, timer or eco mode that shuts the element off, and from radiant heaters when you sit in their line of sight for a few hours, because they warm you instead of the whole room. Oil-filled models store some heat, so they cycle less and give steadier warmth, but they do not make more heat from each kWh.

Is it safe to leave a space heater on overnight?

No. The Consumer Product Safety Commission says never to leave portable heaters on while sleeping, and the National Fire Protection Association says to turn them off and unplug them when you leave the room or go to bed. Use a heater with a tip-over switch, overheat protection and a testing lab seal, plug it straight into a wall outlet, and keep anything that can burn at least 3 feet away.

How much does a 1,500 watt heater cost per month?

At the US average of 18.16 cents per kWh, a 1,500 W heater costs about $65.38 a month if it runs 8 hours a day for 30 days at full power, and about $196.13 if it ran flat out around the clock. If a thermostat keeps it on half the time, that monthly figure drops to about $32.69. In Nevada the same month costs $45.79 and in Hawaii it costs $169.85.

Sources

Figures and rules in this guide were checked against these references for the October 30, 2026 update. The Department of Energy's Energy Saver pages were offline when we checked on October 30, 2026, so those links go to archived copies of the 2026 DOE pages. The cost tables are our own arithmetic from the EIA figures.