How much does it cost to run a space heater?
Last updated: February 2026 · 4 min read
Space heaters are cheap to buy and surprisingly expensive to run. Almost all of that cost comes down to one number: wattage. The vast majority of portable electric heaters draw 1,500 watts on high, and because they turn nearly all of that electricity into heat, the running cost is easy to predict once you know your electricity rate.
The quick answer
At the U.S. average electricity rate of about $0.17 per kWh, a 1,500-watt space heater costs roughly:
- $0.26 per hour running flat out
- ~$2.04 per day if it runs 8 hours
- ~$61 per month at 8 hours a day
Run two of them, or run one around the clock, and it climbs fast. That is why a space heater is great for warming the one room you are in — and a costly way to heat a whole house.
How to calculate it yourself
Cost = (watts ÷ 1,000) × hours × rate ($/kWh)
So a 1,500 W heater for 5 hours at $0.17/kWh = (1500 ÷ 1000) × 5 × 0.17 = $1.28. Your electricity rate is on your utility bill in cents per kWh — use your real rate, since rates range from about $0.10 in the cheapest states to over $0.30 in the most expensive.
Cost by electricity rate (1,500 W heater)
| Rate ($/kWh) | Per hour | 8 hrs/day | Per month (8 hr/day) |
|---|---|---|---|
| $0.10 | $0.15 | $1.20 | ~$36 |
| $0.15 | $0.23 | $1.80 | ~$54 |
| $0.17 (US avg) | $0.26 | $2.04 | ~$61 |
| $0.22 | $0.33 | $2.64 | ~$79 |
| $0.30 | $0.45 | $3.60 | ~$108 |
Does the type of heater matter?
Not much for running cost. Ceramic, infrared, oil-filled, and fan heaters all convert electricity to heat at essentially 100% efficiency — a 1,500 W heater is a 1,500 W heater. What differs is how they spread heat (infrared warms people and objects directly; oil-filled radiators hold warmth longer), which can let you feel comfortable at a lower setting. The only way to truly use less energy is fewer watts or less time.
Ways to cut the cost
- Zone heat. Turn the central thermostat down and use the space heater only in the room you are in. Heating one room beats heating the house.
- Use a timer or smart plug. Stop it running while you sleep or are out. A cheap smart plug with a schedule pays for itself quickly.
- Run a lower setting. Many heaters have a 750 W "low" mode that costs half as much per hour.
- Seal the room. Close doors and block drafts so the heat stays where you are.
- Consider a heat pump for the long haul. If you are heating a space for months, a ductless mini-split heat pump delivers 2–3× more heat per unit of electricity than resistance heaters — higher upfront cost, far cheaper to run.
Run the numbers for your exact heater and rate
Enter your heater's wattage, hours of use, and your local electricity rate to see your real cost per hour, month, and year.
Open the cost-to-run calculatorFrequently asked questions
How much does a 1,500-watt space heater cost per hour?
About $0.26 per hour at the U.S. average rate of $0.17/kWh. At $0.10/kWh it is about $0.15/hour; at $0.30/kWh about $0.45/hour.
Do space heaters use a lot of electricity?
Yes. At 1,500 watts, a space heater is one of the most power-hungry things you can plug into a standard outlet. Running one 8 hours a day adds roughly $50–$80 to a monthly bill in most states.
Is it cheaper to run a space heater or central heating?
For a single room, a space heater is usually cheaper because you only heat the space you are in. For a whole house, central heating — especially a heat pump — is far cheaper than running several space heaters.
Which space heater is cheapest to run?
All electric resistance heaters of the same wattage cost the same to run. To spend less, use a lower wattage setting, run it for less time, or step up to a heat pump, which produces more heat per watt.