Seasonal · 4 min read
Space heater season is starting — here's what it'll cost
Every November, searches for 'how much does a space heater cost to run' spike 5× overnight. The answer depends on three numbers — and one of them isn't the heater.
The short answer
A typical 1,500-watt space heater, running roughly 10 hours a day at US-average rates, adds about $56/month to your bill. That's for one heater, in one room, thermostat-cycling through normal winter usage.
Run two heaters, or keep one going 16 hours a day during a cold snap, and that number doubles fast.
Key insight
Zone heating is the cheat code.
Run your own numbers
The cost depends on how long you run it, the wattage, and your local rate. Plug those in:
Estimated cost
A space heater draws full power only while the thermostat/compressor is running — about 7.5 effective hours at 1500W across your 10-hour window.
The three cheapest things you can do
- Choose the 750W setting unless the room is genuinely cold. Most heaters have a low mode that costs half as much and produces enough heat for a small room.
- Run it on a smart plug with a schedule. Leaving a heater running all day "just in case" doubles the cost for no benefit.
- Pair it with a thermostat adjustment. Drop the central system 5°F when you're actively using a space heater. This is where zone heating actually saves money.
When it's not worth it
If you're heating three or more rooms simultaneously with portable heaters, you've usually lost the savings. Central heat at that point is more efficient per square foot heated. Space heaters win when the question is "do I heat this one room for a few hours or the whole house all day" — not "do I heat four rooms individually."