How much does it cost to run a space heater?
Space heaters are portable electric resistance heating units that convert electrical current directly into heat. Because they run at high wattage and operate throughout the coldest months, they're often the single largest driver of winter electricity consumption in households that rely on them.
Space Heater running cost calculator
- Per day
- $1.53
- Per month
- $15.30
- Per year
- $183.60
- CO₂ / year
- 432 kg
Based on 1080 kWh per year. Adjust the price per kWh to match your latest electricity bill for an exact figure.
At 1500 watts used 6 hours a day, a space heater costs about $1.53 per day, $15.30 per month and $183.60 per year on an average rate of 17¢ per kWh — roughly 1080 kWh and 432 kg of CO₂ over a year. Enter your own electricity rate and usage in the calculator above for a figure matched to your bill.
The reason space heaters consume so much energy is fundamental to how they work. Unlike a central heating system that distributes warmth across an entire home efficiently, a space heater generates all its heat through electrical resistance—a wire filament or ceramic element that becomes extremely hot as electricity flows through it. This 1:1 conversion of electrical energy into heat means there's no efficiency advantage to buying a premium model; a $30 heater and a $200 heater produce nearly identical heat output per watt consumed. The real difference lies in controls, safety features, and thermostat accuracy, not in whether it wastes less energy than a competitor.
Room size matters far more than brand or features when determining how long you'll actually run your heater. A space heater sized for a 200-square-foot bedroom will cycle on and off more frequently in a properly insulated space, cutting runtime significantly compared to the same heater in a 400-square-foot drafty living room. Before buying, measure your target room and check the heater's stated coverage area. Many people make the mistake of buying an undersized heater and running it constantly at maximum output, or overshooting with an overpowered model they'll dial down anyway—both waste money. If your heater never shuts off on its thermostat, it's working harder than it should be.
Placement and usage patterns have outsized impact on your bill. A heater running eight hours daily in a well-insulated bedroom with a closed door will cost far less to operate than the same heater running six hours in a drafty hallway or open-concept space. Sealing air leaks around windows and doors before deploying a space heater is often a smarter investment than upgrading the heater itself. Similarly, using the thermostat feature rather than just leaving it on a fixed heat setting makes a tangible difference. Modern space heaters with digital thermostats and accurate temperature sensing will reach your target temperature and then maintain it with occasional heating cycles, whereas older models or those with mechanical dials tend to overshoot and waste energy.
Safety and electrical capacity deserve equal weight with cost considerations. Space heaters draw heavy current—typically 12 to 15 amps on a 120V circuit—which means they should be plugged directly into a wall outlet on their own circuit, never into a power strip or extension cord. Overloading a circuit creates fire risk and can trip breakers repeatedly. If you find yourself constantly losing power when the heater runs, your home's electrical service may not support running it in that location, and you should either move the heater to a different outlet or have an electrician evaluate your service. Tip-over switches and automatic shutoff timers are inexpensive safety additions that prevent leaving a heater running unattended.
The most effective way to lower your space heating bill is not to buy a different heater, but to examine why you need one at all. Some homeowners use space heaters to heat a single room while heating the entire house—this can make sense for a closed-off guest room you barely use. Others use them to compensate for poor insulation or thermostat issues in their central system. If you're running a space heater eight hours a day, your home insulation, air sealing, or central heating settings may warrant attention first. A space heater should be a targeted solution for a specific cold zone, not a band-aid for a poorly functioning heating system.
Frequently asked questions
- Are expensive space heaters more efficient than cheap ones?
- No. All electric resistance heaters convert electricity to heat at nearly 100 percent efficiency. A $40 basic heater and a $300 model with advanced controls both waste almost no energy; the price difference reflects thermostat precision, build quality, safety features, and warranty, not energy savings. A better thermostat will reduce runtime by maintaining your target temperature more accurately, but that's a control advantage, not an efficiency advantage.
- Can I run a space heater on a power strip or extension cord?
- You should not. Space heaters draw 12 to 15 amps, and power strips and extension cords are typically rated for lower loads. Running a space heater through them creates fire hazard, can melt the cord, and may trip your circuit breaker repeatedly. Always plug directly into a wall outlet, and if that outlet cuts power when the heater runs, do not use that location—move to a different circuit.
- Does leaving a space heater on a thermostat use less energy than turning it on and off manually?
- Yes, if the thermostat works accurately. A functional thermostat will cycle the heater on and off to maintain your target temperature, preventing overshooting and wasted heat. Manual control often leads to leaving the heater on longer than necessary because you either forget to turn it off or overshoot the desired temperature before switching it off. Verify your heater's thermostat is responsive and keeps the room at a consistent temperature rather than swinging between too cold and too hot.
- How much of my electricity bill will a space heater add?
- That depends on your heater's wattage, daily runtime, your regional electricity rates, and how long you use it during winter. See the figures above for your specific usage scenario. The most effective way to lower the impact is to reduce runtime—heat only the room you're in, close doors to unheated areas, seal drafts, and use the thermostat to avoid overheating.
- What's the difference between a ceramic heater and one with a traditional coil?
- Ceramic heaters tend to heat up faster and distribute warmth more evenly because the ceramic element has better thermal properties than a bare coil. Coil heaters are often cheaper upfront but take longer to reach temperature and create hot spots. In terms of energy consumption, both convert electricity to heat at the same rate, so the choice comes down to comfort, safety, and how quickly you want a warm room.
- Should I use a space heater if I have central heating?
- Space heaters make sense for heating a single drafty room or a zone you close off from the rest of the house, especially if lowering your central thermostat would make other areas too cold. They're less economical for supplementing weak central heating throughout your home; in that case, improving insulation, sealing leaks, or fixing your central system is usually more cost-effective. If you rely on a space heater to stay warm in multiple rooms, your central system may need maintenance or adjustment.