how many watts space heater

How many watts does a space heater use?

Heating and cooling bills are some of the biggest expenses of owning or renting property. For that reason, it’s important to know just how much electricity a space heater uses when you’re looking at your whole home’s energy usage.


Key takeaways


  • On average, space heaters use 1,500 watts of electricity.
  • Using a space heater 8 hours per day will use about 84 kilowatt-hours of electricity per week
  • It costs an average of $51.65 to run a space heater for a month, and $258.26 to run for a year
  • The best way to save on electricity is to install solar panels. Start comparing your options on the EnergySage Marketplace today.

In this article

How much electricity does a space heater use?

Generally, space heaters use 1,500 watts (W) of electricity, depending on the model. Most space heaters use about 15 amps, and connect to a 120 volt outlet.

How much you run your space heater has the biggest impact on how much electricity it uses over time. Assuming you run your space heater for 8 hours per day for 5 months of the year:

How much electricity do space heaters use?

Space heater wattageLength of time poweredkWh of electricity used
1,500 W1 hour1.5 kWh
1,500 W1 day12 kWh*
1,500 W1 week84 kWh
1,500 W1 month364 kWh
1,500 W1 year1,820 kWh**

*Assuming 8 hours of operation per day
**Assuming 5 months of operation per year

Different wattage space heaters use different amounts of electricity over the course of a year. Assuming again that the average space heater is run for 8 hours per day for 5 months of the year, here’s how much electricity you’ll use over the course of a full calendar year:

How many watts do different space heaters use in a year?

Space heater wattageHours per year runYearly kWh of electricity
1,200 W1,2131,456 kWh
1,300 W1,2131,577 kWh
1,400 W1,2131,698 kWh
1,500 W1,2131,820 kWh
1,600 W1,2131,941 kWh
1,700 W1,2132,062 kWh
1,800 W1,2132,183 kWh

We’ll mostly be referring to the electricity used by space heaters in terms of kWh in this article. The reason is simple: your electric bill is measured in kWh, and you get charged based on the kWh of electricity you use per month!

Watts, amps, voltage, and more: what do they mean?


There are a lot of terms you can use to describe how electricity flows and is used by appliances. We’ve already mentioned most of them – here are a few definitions to keep things straight:

  • Volts (V): volts (short for voltage) are measures of electrical pressure differences. Put simply, voltage is the speed of electricity passing through a circuit.
  • Amps (A): amps (short for amperes) are a measure of electrical current. Put simply, amps are the amount of electrons (which make up electricity) flowing through a circuit.
  • Watts (W) and kilowatts (kW): multiplying volts x amps gets you watts (or wattage). Put simply, watts are the rate of electricity consumption. A kilowatt is just 1,000 watts.
  • Kilowatt-hours (kWh): lastly, kilowatt-hours are how your electric bill measures your energy usage. Simply put, kilowatt-hours are electricity consumption over time.

You can think of all of these terms like water flowing through a pipe. Voltage is the water pressure, amps are the amount of water flowing past any point, and wattage is the overall rate of water flow through the pipe.

How much does it cost to power a space heater?

When you get your monthly electric bill, you only get to see the total amount you’re charged, not how much each appliance contributes to your final bill. Based on an average wattage of 1,500 W for space heaters (amounting to 1,820 kWh/year if you use your space heater like an average household would) and using state average electricity rates, here’s how the cost to run a space heater pans out over the course of a month and a year:

Monthly and yearly costs to run a space heater by state

StateAverage electricity rateCost per monthCost per year
California22.00 ¢ / kWh$80.08$400.40
New York20.59 ¢ / kWh$74.95$374.74
Texas12.56 ¢ / kWh$45.72$228.59
Massachusetts22.59 ¢ / kWh$82.23$411.14
Florida12.21 ¢ / kWh$44.44$222.22
Virginia12.58 ¢ / kWh$45.79$228.96
New Jersey16.20 ¢ / kWh$58.97$294.84
Maryland14.48 ¢ / kWh$52.71$263.54
Washington10.38 ¢ / kWh$37.78$188.92
US Average14.19 ¢ / kWh$51.65$258.26

Note: average electricity rates are based on October 2021 data from the U.S. Energy Information Administration (EIA).

Looking to offset your electric bills (and the energy these appliances use) with solar? When you sign up (for free!) on the EnergySage Marketplace, you can compare solar quotes from high-quality, local solar installers. Make sure to keep in mind your current and future electricity usage, and talk about how that could change with your installer for the most accurate quotes.

Frequently asked questions about powering a space heater

What’s the best time to run a space heater?

If you’re on a time-of-use (TOU) rate plan, you are charged different amounts for electricity throughout the day. In general, it’s cheaper to use a space heater during “off-peak” hours, which are usually overnight. For a space heater, you may have less of an option, as you’ll just need to run it when it’s colder.

What size battery do you need to back up a space heater?

Most lithium-ion batteries like the Tesla Powerwall or Generac PWRcell have a power rating of 4 to 5 kW or higher, and 10+ kWh of usable capacity. Space heaters use about 1,500 W (1.5 kW) of power at any one time, meaning you’ll be able to power a space heater for a somewhat short amount of time with most batteries. To keep it running for longer, you might need several batteries together.

How many solar panels does it take to power a space heater?

Average space heaters use 1,500 W of electricity to stay powered. On average, solar panels are rated at around 350 W, meaning you’ll be able to power a space heater with four to five solar panels.

What are ENERGY STAR appliances?

ENERGY STAR is a U.S. government-backed system that certifies how energy efficient appliances are. If an appliance is better than the average appliance in its category by a certain amount, it is labeled as “ENERGY STAR certified”. ENERGY STAR appliances cost less money to run, given that they are more efficient with the electricity they use.

How much money can solar panels save you?

Solar savings vary widely, and your unique savings depends on factors like electricity usage, your location, electric rates and plans, and more. In general, most homeowners can expect to save somewhere between $10,000 and $30,000 over the lifetime of a solar panel system. On average, it takes between 7 and 8 years for most homeowners who shop for solar on EnergySage to get their solar panels to pay for themselves.

Going solar is one of the most effective ways to reduce or eliminate your electric bill, and you should make sure you are getting several quotes from reputable installers before you decide to move forward. Visit the EnergySage Marketplace to get solar quotes from installers in your area and begin comparing options.


Posted on by .
Categories: Cost Benefit
Tags: ,

About Jacob Marsh

Jacob is a researcher and content writer at EnergySage, where he's an expert on current issues–and new technology!–in the solar industry. With a background in environmental and geological science, Jacob brings an analytical perspective and passion for conservation to help solar shoppers make the right energy choices for their wallet and the environment. Outside of EnergySage, you can find him playing Ultimate Frisbee or learning a new, obscure board game.

Leave a Reply

Your email address will not be published.