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A space heater looks cheap at the store, but it’s one of the biggest electricity users in most homes. Use this free space heater cost calculator to find out what yours costs to run per hour, per day, per month, and for the whole winter, based on your own electric rate.
How much does your space heater cost to run?
Enter your heater’s wattage, how long you run it, and your electric rate. You’ll get the cost per hour, per day, per month, and for the whole winter.
Your heater
How you use it
- Cost per hour—
- Cost per day—
- Electricity per month—
- Cost for the whole winter—
Estimate only, using the standard appliance energy formula: watts × hours ÷ 1,000 × your rate. How often a heater with a thermostat actually runs depends on the room and the weather. Check your bill for your exact rate.
| Hours per day | Per day | Per month (30 days) |
|---|
Assumes the heater runs nonstop. Enter your own numbers above for a closer estimate.
What’s in This Guide
How to Use the Space Heater Cost Calculator
The space heater cost calculator works in 3 easy steps:
- Pick your heater setting. Most plug-in space heaters run at 1,500 watts on high and around 750 on low. If yours is different, choose “Other” and enter the watts from the label.
- Tell it how you use the heater: how many hours a day, how many days a month, and how many months a winter.
- Enter your electric rate in cents per kWh. It’s on your electric bill. If you don’t have it handy, leave the default of 17 cents, which is close to the current Indiana average.
The “How it runs” setting matters. A heater without a thermostat runs at full power the whole time it’s on. A heater with a thermostat shuts off once the room warms up and kicks back on as it cools, so it uses less. The calculator’s thermostat options are estimates, since how often the heater runs depends on the room and how cold it is outside.
How Much Does a Space Heater Cost to Run?
So how much does a space heater cost to run? A 1,500-watt space heater uses 1.5 kilowatt-hours (kWh) of electricity every hour it runs at full power. At 17 cents per kWh, that’s about 26 cents an hour.
That sounds small, but it adds up fast:
- 4 hours a day: about $1.02 a day, or $30.60 a month.
- 8 hours a day: about $2.04 a day, or $61.20 a month.
- 24 hours a day: about $6.12 a day, or $183.60 a month.
Run one 8 hours a day for a 4-month winter, and you’ve spent about $245 on electricity for one room. Two heaters double that. Indiana’s average residential rate is about 17 cents per kWh, according to EnergyBot, which uses U.S. Energy Information Administration data. Your rate may be higher or lower, so check your bill. Source: EnergyBot — Indiana Electricity Rates
How the Calculator Works
The space heater cost calculator uses the standard formula for estimating any appliance’s energy use. Multiply the wattage by the hours you use it each day, then divide by 1,000 to get kilowatt-hours. Multiply by the number of days, then by your utility rate per kWh to get the cost. Virginia Tech Extension lists portable heaters at 750 to 1,500 watts, which is why the calculator starts with those two settings. Source: Virginia Tech Extension — Estimating Appliance and Home Electronic Energy Use
Virginia Tech says the wattage is usually stamped on the bottom or back of the appliance, or on its nameplate. If the label only lists amps, multiply the amps by 120 volts to get the watts.
The calculator also adjusts for how often the heater actually runs, and multiplies by the number of heaters. If you’re running more than 1,800 watts at once, it warns you, since that’s more than one standard 15-amp household circuit can handle.
Want to know how much a space heater actually draws instead of estimating? A plug-in electricity usage monitor sits between the heater and the outlet and tells you exactly how many kWh it used. Just be sure the monitor is rated for at least 15 amps before you plug a heater into it.
When a Space Heater Saves Money (and When It Doesn’t)
A space heater saves money when it lets you keep the rest of the house cooler. Heating one room you’re sitting in, with the furnace turned down, can cost less than heating the whole house. Running a space heater on top of a furnace that’s still set to 72 degrees just adds to the bill.
A few ways to get more out of the heat you’re paying for:
- Turn the furnace down while you use the heater. Our thermostat savings calculator shows how much a lower setting saves.
- Close the door to the room you’re heating.
- Seal the drafts. A strip of foam weatherstripping around the door and a door sweep keep the warm air in. Here’s how to seal windows and doors for winter.
- Set your ceiling fan to spin clockwise on low to push warm air back down. Here’s the right ceiling fan direction for winter.
Space Heater Safety
Space heaters are a leading cause of home heating fires. The Illinois Office of the State Fire Marshal, citing National Fire Protection Association data, says space heaters and heating stoves caused nearly half of home heating equipment fires and were linked to about 8 in 10 of the deaths from those fires. Its safety rules: Source: Illinois Office of the State Fire Marshal — Space Heater Safety
- Keep heaters at least 3 feet away from anything that can burn, like curtains, bedding, and furniture.
- Turn the heater off when you go to bed or leave the house. Never leave it running unattended.
- Plug it directly into a wall outlet. Never use an extension cord or power strip.
- Buy a heater with an automatic shutoff if it tips over, and one that’s been tested and certified by an independent testing lab.
If you’re shopping for one, look for a space heater with a thermostat and tip-over shutoff. The thermostat keeps it from running nonstop, which saves money, and the tip-over switch shuts it off if it gets knocked over.
Frequently Asked Questions
How much does it cost to run a space heater for an hour?
A 1,500-watt space heater on high costs about 26 cents an hour at 17 cents per kWh. On low, at about 750 watts, it’s roughly half that. Use the space heater cost calculator above with your own rate for an exact number.
How much does it cost to run a space heater all day?
Running a 1,500-watt heater nonstop for 24 hours costs about $6.12 at 17 cents per kWh. That’s over $180 a month if you do it every day.
Is it cheaper to use a space heater or turn up the heat?
A space heater is usually cheaper if you’re heating one room and turn the furnace down for the rest of the house. If you leave the furnace setting where it was, the space heater just adds to your bill.
Do space heaters use a lot of electricity?
Yes. At 1,500 watts, a space heater uses more electricity per hour than most other things you plug in at home. Eight hours a day for a month adds about 360 kWh to your electric bill.
How do I find my space heater’s wattage?
Check the label on the bottom or back of the heater. Most plug-in space heaters top out at 1,500 watts. If the label only lists amps, multiply the amps by 120 to get the watts.