Space Heater vs. Central Heat: Which Actually Costs Less?
The answer depends on one question: how many rooms are you trying to heat?
Last updated: March 15, 2026
Every winter, the same question comes up: is it cheaper to turn up the thermostat or plug in a space heater? The internet is full of conflicting advice, so let's settle it with actual numbers.
The short answer: a space heater is cheaper if you are heating one room and turning down the central heat. Central heat is cheaper if you are trying to heat two or more rooms. The break-even point is usually around two rooms.
The Real Numbers
Here are the monthly costs for different heating scenarios at the national average electricity rate of 16.72 cents per kWh. Your costs will be different depending on your state's rate. Residents of Washington (10.76 cents) pay roughly 35% less for any electric heating scenario, while Hawaii residents (43.21 cents) pay about 2.5x more.
Space Heater
A 1,500W space heater on the high setting, running 8 hours per day:
- Per day: $2.01
- Per month: $60.19
- Per 5-month winter: $300.96
On the low setting (750W), cut these numbers exactly in half.
Two space heaters running simultaneously: double the cost. Three: triple. This is where the math stops favoring space heaters for most households.
Electric Furnace (Central Heat)
An electric furnace at 10,000W running 8 hours per day:
- Per day: $13.38
- Per month: $401.28
That looks enormous, but the furnace heats the entire house, not just one room. And a modern furnace with a thermostat cycles on and off, so it rarely runs at full power for 8 straight hours. Actual average daily run time depends on insulation, outdoor temperature, and thermostat setting. In moderate climates, effective run time might be 3-5 hours per day, bringing the monthly cost to $150-250.
The Comparison
| Scenario | Monthly Cost | Notes |
|---|---|---|
| 1 space heater + central heat off | ~$60 | Cheapest if you only need one room warm |
| 1 space heater + central heat at 62F | ~$60 + $80-120 | Common strategy: supplement with portable, reduce central |
| 2 space heaters, central off | ~$120 | Now you are matching central heat cost |
| Central heat only at 68F | ~$120-200 | Heats entire house evenly |
| 3 space heaters, central off | ~$180 | More expensive than central for less coverage |
The break-even point is clear: one space heater in one room beats central heat on cost. Two space heaters roughly tie. Three or more space heaters lose to central heat every time, and you still have cold hallways and bathrooms.
The Strategy That Actually Saves Money
The winning approach is not "space heater OR central heat." It is both, used strategically:
- Lower your central thermostat to 62-65F (saves 15-25% on central heat)
- Run a space heater in the room where you spend the most time (living room in the evening, bedroom at night)
- Move the heater with you as you move through the house
- Use the low (750W) setting when possible; it is often sufficient in an insulated room
This approach heats the room you are in to 68-72F while keeping the rest of the house at a lower but tolerable temperature. Many families save 20-30% on total heating costs with this strategy.
Better Than Both: The Heat Pump
If you are comparing electric heating options, the conversation should include heat pumps. A mini-split heat pump delivers the same warmth as a 1,500W space heater while drawing only 500-700W, because it moves heat from outside air rather than generating it from scratch. The monthly cost for the same heating output drops from $60 to $20-30.
The catch is upfront cost: a mini-split installed in one room costs $2,000-5,000. But if you are spending $60+/month on a space heater for 5 months per year ($300/year), the heat pump pays for itself in 4-8 years and then saves you money for the next 15-20 years of its lifespan.
For the full comparison, check the electric furnace calculator which includes heat pump cost context.
What About Gas Heat?
If your central heat runs on natural gas rather than electricity, the comparison changes dramatically. Natural gas is typically cheaper per BTU than electricity, so a gas furnace heating the whole house often costs $60-100/month, less than a single electric space heater. In this case, turning up the gas furnace is almost always cheaper than plugging in an electric space heater. The space heater only wins if the gas furnace is off and you only need one room warm for a short period.
Other Alternatives Worth Considering
- Electric blanket ($5-8/month): If you only need warmth in bed, this is far cheaper than any room-heating option.
- Electric fireplace ($3-10/month): Same cost as a space heater when using the heat mode, but adds visual ambiance. The flame-only mode costs under $1/month.
- Infrared heater ($36-60/month): Same wattage cost as a ceramic space heater, but feels warmer faster in drafty rooms because it heats objects directly rather than air.
- Heated towel rack ($0.50-1/month with a timer): Not a room heater, but a 30-minute pre-shower run makes the bathroom bearable without heating the whole room.
The Bottom Line
A space heater saves money when used to heat one room while lowering central heat. It loses money when used in addition to central heat (without lowering the thermostat) or when heating multiple rooms. The sweet spot is one heater, one room, central heat turned down.
For the exact numbers at your state's rate, use the space heater calculator and the electric furnace calculator, or plug both into the bill estimator to see the combined cost.
Frequently Asked Questions
A space heater is cheaper if you heat one room and turn down the central thermostat. Running a 1,500W space heater costs about $60/month at the national average rate. If turning down central heat by 5-8 degrees saves more than $60/month (which it often does in larger homes), the strategy saves money. But if you run the space heater on top of unchanged central heat, you are simply adding cost.
A 1,500W space heater on high for 8 hours costs about $2.01 per night at the national average rate. On the low setting (750W), it costs about $1.00. In Washington (cheapest state), the cost is $1.29 per night on high. In Hawaii (most expensive), it is $5.19 per night. Use the space heater calculator with your state for exact figures.
Yes, especially if you run multiple heaters or leave them on more hours than you realize. Two space heaters running 10 hours per day add $100+/month to your electric bill. The most common mistake is running space heaters in addition to central heat without lowering the thermostat, which means you are paying for both systems at full cost.
All cost estimates on this page use average residential electricity rates from the U.S. Energy Information Administration (EIA) and typical appliance wattage values. Your actual costs will vary based on your specific rate, appliance, and usage patterns. See our full disclaimer.