Space Heater vs. Central Heat: Which Costs Less to Warm One Room?

A 1,500-watt space heater running for an hour uses about 1.5 kilowatt-hours of electricity. At the national average residential price the U.S. Energy Information Administration reported for 2026 so far, a little over 18 cents per kilowatt-hour, that hour costs roughly 27 cents. Run it eight hours a day and you are near $2.20 a day for one heater.

Whether that is a bargain or a budget leak depends on what it replaces. If a space heater lets you turn down the central heat and warm only the room you are using, it can save money. If it runs on top of a fully heated house, it simply adds to the bill. Here is how to tell which situation you are in.

Do the math with your own rates

Your electric bill shows your price per kilowatt-hour, and it may be well above or below the national average. To estimate a heater's hourly cost, multiply its wattage by the hours you use it, divide by 1,000 and multiply by your rate. Most portable electric heaters top out at 1,500 watts, and many have lower settings.

Central heating costs are harder to pin down because they depend on fuel type, system efficiency, home size and insulation. A gas furnace, a heat pump and electric baseboard heat all cost very different amounts to run. Your utility bill history is the best guide: compare a mild month with a cold month to see roughly what heating adds.

The key comparison is not heater versus furnace in general. It is the cost of running the heater compared with the savings from lowering the thermostat for the rest of the house.

When a space heater saves money

Space heaters tend to make the most sense when one or two people spend most of their time in one room. A remote worker in a home office or someone reading in a living room for the evening may be able to keep the rest of the house cooler and warm just that space.

The U.S. Department of Energy notes that you can save money by turning your thermostat back when you are asleep or away. A space heater can extend that idea to rooms you are not using, as long as you actually lower the central thermostat.

Small, well-insulated rooms with the door closed hold heat best. A heater in a large open space with high ceilings will struggle and run longer, which raises the cost.

When central heat is the better deal

If several people are spread across the house, central heat is usually more practical. Running multiple space heaters at once can cost more than a well-maintained furnace or heat pump, and it creates more safety risks.

Heat pumps deserve a special note. Because they move heat rather than create it, modern heat pumps can deliver more heat per unit of electricity than a standard electric resistance heater. If your home has one, a portable heater may not save much, if anything.

The same is true if you have an efficient gas system and relatively cheap natural gas. In that case, electric resistance heat from a space heater can be the pricier option per unit of warmth.

Safety comes first

The National Fire Protection Association reports that space heaters are involved in a large share of home heating fires and most of the deaths from them. Keep anything that can burn, including curtains, bedding and furniture, at least three feet away from the heater, as fire safety agencies advise.

Plug heaters directly into a wall outlet rather than an extension cord or power strip. Look for models with automatic shut-off if tipped over and overheat protection, and choose one certified by a recognized testing laboratory.

Never leave a heater running while you sleep or after you leave the room. Fuel-burning heaters used indoors carry additional carbon monoxide risks, so make sure your home has working carbon monoxide alarms.

Choosing a heater without overspending

You do not need the most expensive model to heat a small room. Most electric space heaters convert electricity to heat at nearly the same efficiency, so a higher price usually buys features such as quieter operation, a thermostat, a timer or a better design rather than more heat per dollar.

A built-in thermostat helps control cost by cycling the heater off once the room is warm. A timer can prevent it from running longer than needed. Both features are worth having.

Be skeptical of marketing claims that a particular heater will cut your heating bill by a large percentage. Savings depend on how you use it and how much you lower your central heat, not on the brand.

A simple one-week test

To see what works in your home, try a test. For one week, use central heat as usual and note your thermostat setting and how warm you feel. The next week, lower the thermostat a few degrees and use a space heater only in the room you occupy most.

Some utilities let you view daily or hourly usage online. Compare the two weeks, keeping in mind that outdoor temperatures will change. Look at the overall trend rather than a single day.

If your total heating cost drops and you stay comfortable, the space heater strategy works for you. If costs rise or the rest of the house gets uncomfortably cold, stick with central heat and focus on other fixes.

Mistakes that raise the bill

The most common mistake is running a space heater while leaving the central thermostat where it was. In that case, the heater simply adds electricity use on top of the normal heating bill. The savings only come when the rest of the house is allowed to run cooler.

Another mistake is heating a room with the door open. Warm air drifts into hallways and other rooms, so the heater runs longer to keep up. Closing the door, and blocking any obvious draft under it, helps the heater do less work.

A third is leaving a heater on high all day out of habit. Use the lowest setting that keeps you comfortable, and turn it off when you leave the room, which is also the safer choice.

A quick test you can run at home

If you want real numbers for your own home, try a simple experiment. Note your electric meter reading before and after an evening of space heater use while keeping the thermostat set lower, then compare it with a similar evening using central heat alone. Check your gas or electric bill for the rate you actually pay. A week or two of notes will tell you more than any general estimate, because every home, heater and rate plan is different.

Other ways to warm one room

Before buying a heater, check for cheaper fixes. Closing doors to unused rooms, sealing obvious drafts and using window coverings can help keep heat where you want it. Our separate guide compares thermal curtains, rugs and draft stoppers.

Dressing warmer indoors, using a heated throw blanket or wearing slippers costs very little and can make a lower thermostat setting comfortable. A heated blanket generally uses far less power than a space heater.

If your heating bills are hard to manage, contact your utility about budget billing or assistance programs. The federal Low Income Home Energy Assistance Program helps eligible households with heating costs.