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The short answer: A typical 1,500 watt space heater uses 1.5 kilowatt hours (kWh) of electricity per hour of operation, which costs about $0.18 to $0.30 per hour at average U.S. rates. Running it 8 hours a day for a month adds roughly $43 to $72 to your electric bill.
Every space heater has a wattage rating printed on it, usually between 750 and 1,500 watts for personal use. Wattage measures how much electricity the heater draws per hour. To convert watts to kilowatt hours (the unit your utility bills), divide by 1,000. So a 1,500 watt heater uses 1.5 kWh per hour. A 750 watt heater uses 0.75 kWh.
Your actual cost depends on your electricity rate, which varies by state. The national average is around $0.16 per kWh, but it can be as low as $0.10 in some areas and above $0.30 in others. You can find your exact rate on your monthly bill, just look for the price per kWh.
Using the national average of $0.16 per kWh, here are the per hour costs for common heater sizes:
If you run a 1,500 watt heater for 8 hours a day, that is $1.92 per day. Over a 30 day month, that becomes $57.60. If your rate is higher, say $0.25 per kWh, the same heater costs $0.375 per hour and $90 per month for 8 hours daily. Running it 24/7 would cost $8.64 per day or $259 per month at the national average, which is why most people use space heaters only for supplemental warmth.
Space heaters are intentionally power hungry because they convert nearly all electricity directly into heat. Unlike central heating, they do not distribute warmth through ducts, so they need high wattage to warm a small area quickly. That is why they are best for heating one room while you are in it, not for whole house heating.
To keep costs down, follow these practical tips:
For more help choosing an efficient model, check out the 2026 Space Heaters: DREO Ceramic, Oil Radiators & Garage Picks, which compares top rated options.
Different heater types use the same amount of electricity for the same wattage, but they feel different because of how they distribute heat. Ceramic fan heaters blow hot air directly, so you feel warm faster, but they turn on and off frequently, which can use slightly more electricity over time if you leave them on. Oil filled radiators heat the oil and then radiate heat slowly, so they run less often once the room is warm, potentially using less electricity over a few hours.
Infrared heaters heat objects directly rather than the air, so they can make you feel warm sooner, but they still draw the same wattage. In practice, the biggest factor is not the type but the wattage and how long you run it. A 1,500 watt oil radiator uses the same per hour as a 1,500 watt ceramic heater.
To know exactly what your heater costs, do this simple math:
For example, if you run a 1,500 W heater for 5 hours a day at $0.14 per kWh: 1.5 x 5 x 0.14 = $1.05 per day, or $31.50 per month. That is a reasonable estimate for most people who use a space heater a few hours each evening.
Often yes, if you use it strategically. Central heating warms the whole house, including empty rooms. A space heater can warm only the room you are in. For example, if your central heating uses 40,000 BTU per hour (about 11.7 kW), it costs $1.87 per hour at $0.16 per kWh. A 1,500 watt space heater costs only $0.24 per hour. Even if you run the space heater 8 hours a day, it is $1.92, far less than running central heating for the same time.
However, if you try to heat multiple rooms or a large open area, space heaters become inefficient because you would need several, and the total wattage adds up quickly. They are best for single rooms up to about 300 square feet.
How much does a space heater cost to run per month? A 1,500 watt heater run for 8 hours a day at the national average rate of $0.16 per kWh costs about $57.60 per month. Your actual cost depends on your local rate and usage hours.
Do space heaters use a lot of electricity compared to AC? Yes, per hour they use more than a typical window air conditioner (which uses around 500 to 1,200 watts). But because you usually run them for shorter periods and only in one room, the monthly cost can be lower than running central AC all day.
Can I use a space heater on a 15 amp circuit? Yes, a 1,500 watt heater draws about 12.5 amps, which is within the 15 amp limit for most household circuits. But avoid plugging anything else into the same circuit, as that could trip the breaker.
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