A standard 1,500-watt space heater costs about 27¢ an hour to run at the US average residential electricity rate of 18.31¢ per kWh (EIA, July 2026). Run it on high for 8 hours a day and that is about $2.20 a day and $66 a month. On a 750-watt low setting the cost halves. Where you live matters more than which heater you buy: the same 8 hours a day costs about $46 a month in Louisiana and about $121 in California. Consumer Reports’ own estimate lands in the same place, at roughly $2.10 a day and $64 a month for 8 hours of use.
Try your own numbers in the space heater cost calculator, which has every state’s rate built in.
The Math: Watts × Hours × Rate
Every plug-in electric heater works the same way. It turns electricity into heat, and nearly all of the power it draws ends up as heat in the room. That means the running cost comes from three numbers:
- Wattage. Printed on the label. Most heaters are 1,500 W on high. A typical ceramic model such as the Lasko CD09250 runs 1,500 W on high and 900 W on low.
- Hours. How long the heating element is actually on.
- Your rate. The price per kWh on your bill.
Divide watts by 1,000 to get kilowatts, then multiply: 1.5 kW × 1 hour × $0.1831 = $0.27. The brand, the shape and “eco” marketing don’t change that equation. A $30 heater and a $300 heater with the same wattage cost the same to run for the same hours. What the pricier ones can do is run less, because a good thermostat switches the element off once the room is warm.
Why almost every heater is 1,500 watts
The number comes from household wiring. The electrical code (NEC 210.23) limits a cord-and-plug appliance to 80% of a circuit’s rating, which works out to 1,440 W on an ordinary 15-amp, 120-volt circuit. That makes about 1,500 W the practical ceiling for any heater meant for a normal outlet. It also means that in a single room, no plug-in heater produces much more heat than any other on its high setting.
What It Costs by Setting and Hours
At the US average rate of 18.31¢ per kWh:
| Heater setting | Per hour | 8 hrs/day, per month | 8 hrs/day, 4-month winter |
|---|---|---|---|
| 1,500 W (high) | $0.27 | $66 | $264 |
| 900 W (low) | $0.16 | $40 | $158 |
| 750 W (low / eco) | $0.14 | $33 | $132 |
| 400 W (personal) | $0.07 | $18 | $70 |
Those assume the element runs the whole time. A heater with a working thermostat cycles off when the room reaches its set temperature, so a well-insulated small room can cost noticeably less than the table. A drafty room in January won’t.
Your State Changes the Bill Most
Residential electricity prices ranged from under 13¢ to 48¢ per kWh in July 2026 (EIA). Running a 1,500 W heater 8 hours a day for 30 days uses 360 kWh, which costs:
| State (July 2026 rate) | Per hour | Per month |
|---|---|---|
| Louisiana (12.72¢) | $0.19 | $46 |
| Utah (13.12¢) | $0.20 | $47 |
| Texas (15.88¢) | $0.24 | $57 |
| US average (18.31¢) | $0.27 | $66 |
| New York (29.90¢) | $0.45 | $108 |
| California (33.61¢) | $0.50 | $121 |
| Hawaii (48.00¢) | $0.72 | $173 |
Rates are also still rising. The national average was 17.45¢ in July 2025, and EIA’s September forecast has the average at 18.2¢ for 2026 and 18.6¢ for 2027. EIA’s full winter outlook for heating costs is due October 6.
State averages are a starting point. Your bill’s all-in rate, with delivery and fixed charges spread across your usage, is the number to use if you have it. Divide the bill total by the kWh used.
Does a Space Heater Save Money?
Only when it lets you turn the central heat down. Consumer Reports’ testing found space heaters warm roughly 150 to 200 square feet, one room, and its advice is that they save money only as supplemental heat. The savings case works like this: you sit in one heated room, the thermostat for the rest of the house drops several degrees, and the furnace or heat pump runs less. Leave the central thermostat where it was and the space heater is pure added cost.
It helps to compare what a unit of heat costs from each source. Using a million Btu as the unit, our math with EIA’s prices:
- Electric resistance (any space heater or baseboard) at 18.31¢ per kWh: about $54.
- Heat pump at the same rate, assuming a seasonal efficiency of 2.5 units of heat per unit of electricity: about $21.
- Natural gas furnace at 95% efficiency, using EIA’s winter 2025-26 assumption of $13.50 per thousand cubic feet: about $14.
Resistance heat is the most expensive common way to warm a home, roughly four times gas at those prices. A space heater wins only by heating less space, never by heating it more cheaply. If you already have a heat pump, a space heater costs about two and a half times as much for each unit of heat it delivers.
Electric Blanket vs Space Heater
If the goal is to stay warm in bed or on the couch, an electric blanket is the cheaper tool by a wide margin. Blankets and heated throws draw a small fraction of a heater’s power; around 100 W is a reasonable working figure (our estimate; the label on yours gives the exact number, and many settings draw less). At the US average rate:
| 8 hours a night | Energy | Cost per night | Per month |
|---|---|---|---|
| 1,500 W space heater | 12 kWh | $2.20 | $66 |
| 100 W electric blanket | 0.8 kWh | $0.15 | $4.40 |
The blanket warms you rather than the air, so the room stays cold. For sleeping that is usually fine, and it pairs well with a lower overnight thermostat setting. That is where the real savings come from.
Safety Costs More Than the Electricity
Space heaters cause far more deaths than their share of fires suggests. In NFPA data for 2019 to 2023, space heaters were involved in 29% of home heating fires but 77% of the deaths from them, and nearly half of heating fires happen between December and February. The Consumer Product Safety Commission’s basic rules:
- Plug the heater directly into a wall outlet, never an extension cord or power strip. A 1,500 W load is close to what a household circuit can carry.
- Keep 3 feet of clearance from bedding, curtains, furniture and anything else that burns.
- Turn it off when you sleep or leave the room. For overnight warmth, that is another point for the blanket.
- Use a heater with tip-over and overheat shutoff, and a safety certification mark.
What This Winter May Look Like
NOAA’s Climate Prediction Center expects a strong El Niño this winter, which tilts the odds toward a milder-than-normal December to February across the West and northern tier of the country. A mild winter means fewer heater hours. The rate per kWh, though, is set by your utility and has been rising, so per-hour costs are unlikely to fall.
The Bottom Line
A 1,500 W space heater costs about 27¢ an hour at the 2026 national average rate, about $66 a month at 8 hours a day, and far more in high-rate states. It saves money only when it replaces central heat you’ve turned down, and it costs about four times as much per unit of heat as a gas furnace. For warmth in bed, a 100 W-class electric blanket does the job for about 15¢ a night. Put your wattage, hours and state into the space heater calculator, and if you’re weighing a bigger fix, see the heat pump payback calculator and our guide to winter heating costs in 2026.
FAQ
How much does it cost to run a space heater for 24 hours?
A 1,500 W heater running on high for a full day uses 36 kWh. At the US average rate of 18.31¢ per kWh (EIA, July 2026), that is about $6.59. A thermostat that cycles the element off will lower it, but running any heater around the clock is expensive: about $198 over 30 days.
Is it cheaper to run a space heater or central heat?
It depends on how much of the house you heat. Per unit of heat, a space heater is the most expensive option: about $54 per million Btu at the average rate, versus about $14 for a 95% gas furnace and $21 for a heat pump. A space heater comes out ahead only if it lets you turn the central thermostat down for the rest of the home.
Do “energy-efficient” space heaters use less electricity?
Not per hour at the same wattage. All electric resistance heaters convert power to heat at essentially the same efficiency, so a 1,500 W heater draws 1,500 W whatever the brand. Models with accurate thermostats, timers and eco modes can cut the bill by running fewer hours or at lower wattage.
How much does a space heater add to the electric bill?
About $66 a month for a 1,500 W heater used 8 hours a day at the US average rate, or roughly $264 over a 4-month heating season. In a cheap-power state like Louisiana it is about $46 a month; in California about $121.