How Much Does It Cost to Run a Space Heater?
A typical electric space heater draws 1,500 watts on high. At the 2024 US average rate of $0.16/kWh that is $0.24 an hour. Run it 6 hours a day — a couple of hours before work and the evening after it — and that is $43.20 a month and $216 over a 5-month winter. The calculator opens on exactly that scenario. Change the wattage, the hours and your state, and everything below follows.
Setting
How long it is on
How much of that the element runs
Space heater cost per month
$43.20
270 kWh a month at $0.16/kWh — $216 over a 5-month heating season (1,350 kWh). That is the "morning and evening" habit.
Per hour
$0.24
1.50 kWh an hour, flat out
Per day
$1.44
9.0 kWh a day
Per winter
$216
5 months of this habit
1,500 W ÷ 1,000 × 6 hours = 9.0kWh × $0.16 = $1.44 a day. That is the ceiling: it assumes the element never cycles off. Drop the runtime below to see what a thermostat in a room that holds its heat does to the figure.
The same heat from a heat pump: $17.28 a month
Resistance heat delivers one unit of heat per unit of electricity, so the 270 kWh above is also the heat the room got. A heat pump at a seasonal COP of 2.5 moves that much heat for 2.5 times less electricity. That gap is the entire argument against space heaters — and why they only save money when they heat fewer rooms than the central system would. Run the room-by-room comparison.
Wattage is the figure on the heater's rating plate — 1,500 W on high for virtually every plug-in model, because that is what a 15-amp outlet carries. Element runtime is the share of the switched-on hours the heater is actually drawing power; with no thermostat it is 100%, and with one it depends on your room rather than your heater, so the honest way to find yours is a plug-in energy meter. Monthly figures use a 30-day month and the season is 5 months, the same heating season our furnace page assumes. Not sure of your rate? Check average rates by state.
Want the cost for a different appliance or your exact rate? Use the appliance cost calculator or compare a heater against other devices on the efficiency rankings.
The Formula
Cost = (watts ÷ 1,000) × hours per day × days × price per kWh
Dividing watts by 1,000 converts to kilowatts (kW). Multiplying by hours gives kilowatt-hours (kWh) — the unit your utility bills you in. Multiply by your price per kWh and you have the cost.
Worked example (1,500W heater, 6 h/day, 30 days, $0.16/kWh): (1,500 ÷ 1,000) × 6 × 30 × 0.16 = 1.5 kW × 180hours × $0.16 = $43.20 per month.
Monthly Winter Cost by Hours per Day
The wattage barely varies between heaters. The hours are the entire answer, and they are the number most people guess at. Below is a 1,500W heater at $0.16/kWh, priced by the habit rather than by the hour — from evenings only up to never switching it off. The season column is a 5-month winter, which is the same heating season our furnace page assumes.
| Hours per day | kWh per day | Cost per day | Cost per month | Cost per 5-month winter |
|---|---|---|---|---|
| 4hEvenings only | 6.0 | $0.96 | $28.80 | $144 |
| 6hMorning and evening — what the calculator opens on | 9.0 | $1.44 | $43.20 | $216 |
| 8hA workday at home | 12.0 | $1.92 | $57.60 | $288 |
| 12hWaking hours | 18.0 | $2.88 | $86.40 | $432 |
| 24hAround the clock | 36.0 | $5.76 | $172.80 | $864 |
No yearly column, because nobody runs a space heater in July — a winter is the honest period for a heater, the way a year is for a fridge. Every figure assumes the element is drawing its full 1,500W for all of those hours, which makes them ceilings: a heater with a thermostat in a room that holds its heat spends much of the time coasting. At the 50% runtime of the “warms up, then coasts” preset in the calculator, the 6-hour row falls from $43.20 to $21.60 a month. The 750W low setting halves it again.
Monthly Cost by Electricity Rate
Your rate is the other half of the bill. This table crosses the three winter scenarios with rates from cheap-hydro states to Hawaii. Find your rate on your bill — it is under “energy charge” or “price per kWh” — then read across from the habit that matches yours.
| Rate ($/kWh) | 4h/day | 6h/day | 8h/day | 6h · whole winter |
|---|---|---|---|---|
| $0.10 | $18.00 | $27.00 | $36.00 | $135 |
| $0.13 | $23.40 | $35.10 | $46.80 | $176 |
| $0.16 (US avg) | $28.80 | $43.20 | $57.60 | $216 |
| $0.20 | $36.00 | $54.00 | $72.00 | $270 |
| $0.30 | $54.00 | $81.00 | $108.00 | $405 |
Monthly figures assume a 30-day month and a heater running at its full 1,500W. Lower settings (often 750W) cost about half as much, and a thermostat that cycles the heater off cuts the cost further.
Space Heater vs. Central Heat
A space heater is 100% efficient and still buys the most expensive heat in the house.
Those two things are not in tension. Efficiency is what fraction of the energy you buy becomes heat — resistance heat scores 100% and cannot do better. Price is what that heat costs, and the only fair way to compare a heater against a furnace is per unit of heat actually delivered into the room. On that axis, at $0.16/kWh:
| How the heat is made | Cost per million BTU delivered | vs. a space heater |
|---|---|---|
| Space heaterElectric resistance — one unit of heat per unit of electricity. | $46.89 | — |
| Electric furnace or baseboardThe same resistance heat, ducted. Identical price per BTU. | $46.89 | — |
| Gas furnace (90% AFUE)At $1.50 a therm, blower included. | $17.56 | 2.7× cheaper |
| Heat pump (COP 2.5)Moves heat rather than making it, so it beats 100% several times over. | $18.76 | 2.5× cheaper |
So a space heater can only win by heating less. In a 5-room home, the break-even is about 2.0 rooms against a heat pump at a seasonal COP of 2.5 and 1.9 rooms against a 90% AFUE gas furnace at $1.50 a therm. Heat one room, turn the central thermostat down, and you save. Plug in a second and a third heater and you are paying 2.5× the heat pump's price and 2.7× the furnace's for warmth you could have had from the system you already own.
The one case where the arithmetic flips entirely: if your central heat is an electric furnace or electric baseboard, it is the same resistance heat at the same price per BTU, so zone heating with a plug-in heater can only ever save you money.
Cost by U.S. Region
A space heater uses identical electricity everywhere — there is no efficiency standard, no climate adjustment, nothing about the machine that differs by state. Only the price of a kilowatt-hour changes, which makes this one of the few appliances whose bill is set almost entirely by where you plug it in. The same 1,500W heater at 6 hours a day costs $33.08 a month across the West South Central and $70.11 in New England — 2.1 times the money for the same warm room.
| Region | Avg rate | Cheapest → priciest state | 4h/day · month | 6h/day · month | 8h/day · month | 6h · winter |
|---|---|---|---|---|---|---|
| West South Central4 states · Texas is the big grid here; Arkansas, Louisiana and Oklahoma are cheaper still. | $0.123 | AR $0.115 → TX $0.140 | $22.05 | $33.08 | $44.11 | $165 |
| East South Central4 states · Kentucky and Tennessee anchor the cheap end of the map. | $0.125 | KY $0.116 → AL $0.139 | $22.47 | $33.70 | $44.94 | $169 |
| Mountain8 states · Idaho and Utah have the cheapest power in the country; Colorado the priciest in the division. | $0.126 | ID $0.101 → CO $0.147 | $22.66 | $33.98 | $45.31 | $170 |
| West North Central7 states · Plains and Upper Midwest — every state here is under the national average. | $0.132 | ND $0.117 → MN $0.143 | $23.70 | $35.54 | $47.39 | $178 |
| South Atlantic9 states · Nine jurisdictions from Florida to Delaware, all of them below the national average. | $0.138 | NC $0.121 → MD $0.156 | $24.81 | $37.22 | $49.63 | $186 |
| East North Central5 states · The Great Lakes states, clustered a few cents either side of $0.15. | $0.155 | IN $0.140 → MI $0.178 | $27.98 | $41.97 | $55.97 | $210 |
| Middle Atlantic3 states · New York prices near $0.22 while Pennsylvania sits close to the middle of the country. | $0.188 | PA $0.165 → NY $0.221 | $33.92 | $50.89 | $67.85 | $254 |
| Pacific5 states · The widest spread of any division — Washington hydro at one end, Hawaii's oil-fired island grid at the other. | $0.229 | WA $0.114 → HI $0.388 | $41.29 | $61.94 | $82.58 | $310 |
| New England6 states · Six states, not one of them priced below the national average. | $0.260 | VT $0.213 → CT $0.293 | $46.74 | $70.11 | $93.49 | $351 |
| United States averageWhat the calculator opens on until you pick your state. | $0.160 | ID $0.101 → HI $0.388 | $28.80 | $43.20 | $57.60 | $216 |
States are grouped into the nine US Census divisions, and each division's rate is the plain average of its member states — every state counts once, however many people live there. Which is why the range column matters as much as the average: the Pacific division runs from Washington at $0.11 to Hawaii at $0.39 — 3.4 times over, inside one row. By state the extremes are $136 a winter in Idaho against $523 in Hawaii. Use your own figure from electricity rates by state — or pick your state in the calculator above. One thing the table cannot capture: winter is longer in the north, so the states with the coldest weather and the states with the highest rates are not the same list, and a New England reader should stretch the 5-month season as well as the rate.
Why Space Heaters Cost What They Do
Almost all of them are 1,500W
Standard household outlets are on 15-amp circuits, and 1,500W is the safe maximum a plug-in heater can draw continuously. That is why ceramic, infrared, oil-filled, and fan-forced heaters all converge on the same 1,500W high setting — and why they cost the same to run at that setting. Marketing about “efficiency” rarely affects the electricity bill.
Electric resistance heat is ~100% efficient — but expensive
A space heater turns essentially all the electricity it draws into heat, so it is 100% efficient at the outlet. The catch is that electricity is an expensive way to buy heat: $47 per million BTU at the US average rate, against $19 from a heat pump and $18 from a gas furnace. A heat pump moves heat instead of making it, so it delivers the same warmth for a fraction of the cost.
The thermostat is why your bill is lower than the table
Every table above assumes the element draws its full 1,500W for every switched-on hour. A heater with a thermostat does not: it heats the room, shuts the element off, and coasts until the temperature drops. How much of the time it coasts is a property of your room — its insulation, its draughts, the outdoor temperature — not of the heater, which is why the calculator asks rather than assuming. Halve the runtime and you halve the bill.
Zone heating is where they save money
The smart way to use a space heater is to heat only the room you are in and turn the central thermostat down. In a 5-room home that works out to about 2.0 rooms against a heat pump before the central system is cheaper again. Running several heaters to warm the whole house always costs more than central heat, unless the central heat is resistance too.
What the Central System Costs Instead
The heater is only half the decision. Both figures below come from the models on those pages, priced against the same $0.16/kWh.
A furnace buys heat for $18 a million BTU
A gas furnace throws some of its heat up the flue and still beats a space heater 2.7× on price, because a therm is cheap next to a kilowatt-hour. An electric furnace is the opposite: 100% efficient, and identical to your space heater at $47 a million BTU, which is why homes with electric furnaces have nothing to lose by zone heating. Cost to run a furnace works both fuels against each other, including the break-even gas price.
A heat pump buys the same heat for $19
A heat pump moves heat rather than making it, so it delivers several units of heat per unit of electricity — 2.5× cheaper heat than the heater in your living room, off the same meter. The catch is the cold: its efficiency falls as the outdoor temperature does, and below its balance point the backup resistance strips take over — which is a space heater the size of your whole house. Cost to run a heat pump prices what those strips do to a winter bill.
And if the power is out, you are making the electricity yourself
1,500W is a serious load for a portable generator, and generator fuel costs several times what grid electricity does per kWh. See cost to run a generator before you plan on riding out an outage with a plug-in heater.
Tips to Lower Your Cost
Use a thermostat or eco setting
A heater that cycles off once the room is warm can use far less than its full-power rating — only the runtime counts. Halving it takes the 6-hour habit from $43.20 to $21.60 a month.
Run the low setting
The 750W setting draws half the power of 1,500W — and half the cost, $21.60 a month at 6 hours a day — which is often enough for a small or already-warm room.
Cut the hours before the watts
Going from 8 hours a day to 4 saves $28.80 a month and $144 a winter — a timer or a smart plug does it without you remembering.
Seal drafts first
A weatherstripped door or a draft stopper keeps the heat in, so the heater cycles on for fewer of the hours it is switched on. See our energy savings guide.
Recommended picks
Efficient Space Heaters Worth a Look
Since nearly all plug-in heaters draw the same 1,500W, the real savings come from heaters that let you run a lower setting, hold heat, or shut off on a thermostat. These categories do that well.
Infrared Quartz Space Heater
Whole-room infrared
Infrared heaters warm objects and people directly, so a room feels warm faster — useful for zone heating one occupied room.
Ceramic Tower Heater with Thermostat
Thermostat + eco mode
A built-in thermostat cycles the heater off once the room is warm, so it draws far less than its full 1,500W rating.
Oil-Filled Radiator Heater
Quiet, steady heat
Holds heat well and runs silently — good for bedrooms where a low (often 700W) setting keeps a small room comfortable.
Energy-Saving Smart Plug-In Heater
App + schedule control
Schedule on/off times and eco modes from your phone so the heater only runs the hours you actually need it.
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Related Guides
Space Heater vs. Central Heat
The break-even, room by room, with a calculator
Cost to Run a Furnace
What the central system costs — gas and electric compared
Cost to Run a Heat Pump
$19 a million BTU — and what the backup strips do to that
Electricity Rates by State
Find your state's average rate
Cost to Run an Air Fryer
Another cycling 1,500W element — per-use and monthly cost tables
Most Efficient Appliances
See which appliances cost the most to run
How to Save on Energy Bills
Practical tips by room with savings
Cost to Run a Generator
What this 1,500W heater costs when the power is out and you're making it yourself
Frequently Asked Questions
How much does it cost to run a 1,500W space heater?
At the 2024 US average rate of $0.16/kWh, a 1,500W space heater costs about $0.24 an hour. Run it 6 hours a day — a couple of hours in the morning and the evening — and that is $1.44 a day, $43.20 a month, and $216 across a 5-month heating season. Four hours a day comes to $28.80 a month and eight hours to $57.60.
How do I calculate my own space heater cost?
Use this formula: cost = (watts ÷ 1000) × hours per day × days × price per kWh. Find the wattage on the heater's label or rating plate (most plug-in heaters are 1500W on high), and find your price per kWh on your electricity bill under 'energy charge' or 'price per kWh.' Multiply it out for the period you care about. If your heater has a thermostat, the hours to use are the hours the element is actually drawing power, not the hours the heater is switched on — which is why a real bill usually lands under the table figure.
Are space heaters cheaper than central heating?
Per unit of heat, no — a space heater buys the most expensive heat there is. At $0.16/kWh, electric resistance heat costs about $47 per million BTU delivered, against roughly $18 from a 90% AFUE gas furnace at $1.50 a therm and $19 from a heat pump at a seasonal COP of 2.5. A space heater saves money only by heating less of the house: in a 5-room home the break-even is about 2.0 rooms against that heat pump and 1.9 against the gas furnace. Heat one room and turn the central thermostat down and you win; run three heaters and you have simply paid more.
Do all space heaters use the same amount of electricity?
Almost all plug-in electric space heaters — whether ceramic, infrared, oil-filled, or fan-forced — top out at 1,500W on their highest setting, because that is the safe limit for a standard 15-amp household outlet. They all convert essentially 100% of that electricity into heat, so at the same wattage they cost the same to run. The differences are in how the heat feels and how evenly it spreads, not in efficiency. Using a lower setting (often 750W) or a thermostat to cycle the heater off cuts the cost.
Does it cost more to run a space heater where I live?
Yes, and by more than most people expect, because the heater itself uses identical electricity everywhere — only the price changes. The same 1,500W heater at 6 hours a day costs about $33.08 a month across the West South Central and $70.11 across New England — 2.1 times the money for the same warmth. By state the spread is wider still: $136 a winter in Idaho against $523 in Hawaii.