How Much Electricity Does a Space Heater Use?

If you're in the market for a portable electric space heater, remember to consider the operating costs. Here's what you need to know.

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Moving to sunny Texas from frigid Minnesota brought dreams of outdoor living, at least for more than four months out of the year. So I put a home office in the garage. We have a mosquito screen and a home theater, and my spouse and I sit out there even when the temperature dips into the 40s. How? Hello, space heater.

Space heaters direct warmth right at the user, making them a viable option to boost a chilly room or substandard heating system. But as Christmas 2022’s “bomb cyclone” proved, a space heater can only do so much. We moved inside.

Do you have a space heater? Do you know how much it costs to run? Read on to find out your heater’s impact on your bottom line.

How Many Watts Does a Space Heater Use?

Electric space heaters for home use are usually rated for 1,500 watts at max power. That’s according to Ace Hardware, in partnership with Lasko, maker of home comfort products. (Putting your heater on a low setting will use less energy.)

How Much Electricity Does a Space Heater Use?

A 1,500-watt electric space heater draws 12.5 amps of electricity at 120 volts. (Watts = amps x voltage.) But what does that mean for your electric bill?

The utility doesn’t charge you for electricity in amps. It charges you for power consumed, and that’s measured in kilowatt-hours (kWh).

To figure out how many kilowatt-hours a space heater uses, and therefore how much it costs to run it, take the space heater rating in watts and multiply it by how many hours per day you use it. Then divide that number by 1,000 to convert to kWh.

Let’s say you have a home office in your garage like I do, and you use your 1,500-watt space heater eight hours per day. So 1,500 watts x 8 hours per day / 1000 = 12 kWh. As of November 2022, the average cost of electricity in the U.S. was $0.163 per kilowatt-hour. So 12kWh x $0.163 = $1.96 per day.

Bottom line: Your 1,500-watt space heater running eight hours per day will cost you about two dollars per day to operate, depending on your electricity rate.

Fhm How Much Electricity Does A Space Heater Use?Family Handyman

Do Space Heaters Use a Lot of Electricity?

It depends on how you look at it.

Heat producers like dryers, space heaters and furnaces generally use more energy than electronic devices like computers. Because we know how to calculate the energy costs of your space heater, let’s compare those numbers to other appliances and devices in your home.


Check the back of your TV to see how many watts it typically uses. Mine is 73 watts, about average for its size. You guessed it! A 73-watt television consumes much less power than a 1,500-watt space heater.

Running four hours a day, a 73-watt TV costs about a nickel per day to operate, or a little more than $17 per year. And that doesn’t include vampire energy. In comparison, a 1,500-watt space heater running four hours a day costs nearly $1 per day, or about $88 for three months of daily winter usage.

Laptop computer

Laptops draw power through their charger and use the battery when not plugged in. A laptop’s energy use varies depending on what it’s doing. Checking email will use significantly less energy than running a game.

A 96-watt laptop charging two hours a day costs about three cents daily, or $11.42 per year.

Vacuum cleaner

A vacuum cleaner uses 1,000 to 1,440 watts, although models vary (mine is only 840W). To find your specific energy usage, look at the label on your vacuum. Multiply the amps times the voltage to get the power consumed (in watts), then use the formula.

A 1,000-watt vacuum cleaner used one hour per week consumes one kWh of energy. At the average rate of $0.163 per kWh, the vacuum cleaner costs about $8.50 per year to run.

Clothes dryer

The average family does 300 loads of laundry per year. That’s about $245 per year for a 5,000-watt clothes dryer, making it one of the biggest energy users in your home. A 1,500-watt space heater running for the same 300 hours would cost $73.35 at the average electricity rate cited above.

Ally Childress
Ally Childress is a licensed electrician and freelance writer living in Dallas, Texas.