Billowatt

Space Heater vs Heat Pump: Which Costs Less to Run?

This is the classic winter question: keep the whole-house heat pump doing its job, or shut the bedroom door and run a space heater? The physics differ completely — a space heater converts electricity to heat 1:1, while a heat pump moves 2–4 units of heat per unit of electricity.

Space Heater · per month

$68.58

8 hours/day · 750–1,500 W

Heat Pump · per month

$137

8 hours/day · 1,000–5,000 W

Verdict

Per unit of heat delivered, the heat pump wins by a wide margin — typically 2–4× cheaper. The space heater only wins when it lets you heat one small room while the heat pump (and the rest of the house) stays turned way down. Heating multiple rooms with space heaters is the most expensive common heating mistake in America.

Side by side

Space Heater Heat Pump
Typical power750–1,500 W1,000–5,000 W
Typical usage8 hours/day8 hours/day
Energy per month365 kWh730 kWh
Cost per month (US avg)$68.58$137
Cost per year (US avg)$823$1,647
Cost per month in Hawaii$170$340

Rates as of April 2026. Adjust the assumptions on each appliance's page: Space Heater · Heat Pump.

Frequently asked questions

Which is cheaper to run: a space heater or a heat pump?

At typical usage and the current U.S. average rate (18.8¢/kWh), the space heater is cheaper: about $68.58/month versus $137/month for the heat pump — a difference of $68.58 per month.

How much could I save per year by choosing the space heater?

About $823 per year at typical usage and average rates. In Hawaii (46.6¢/kWh) the annual gap grows to roughly $2,040.

Do these numbers apply to my state?

The ratio between the two stays the same everywhere, but the dollar gap scales with your rate — from North Dakota at 12.4¢/kWh to Hawaii at 46.6¢/kWh. Open each appliance's page for the exact cost in your state.