Energy Calculators

Space heater and AC running cost

See what an electric space heater or a window air conditioner costs to run in your state.

At the U.S. average residential price of 18.16¢/kWh in August 2026 (EIA), running a 1,500 W space heater 8 hours a day costs about $65.38 a month; an 8,000 Btu/h air conditioner with an EER of 11 (727 W) costs about $31.70.

Pre-fills the average residential price (Aug 2026, EIA).

W

On the label; most plug-in heaters are rated up to 1,500 W.

h/day

Thermostats cycle units on and off; count running time, not time switched on.

days
¢/kWh
Per month (30 days)
$65.38360 kWh
Per season (90 days)
$196.13
Per day
$2.18
Per hour running
$0.2721,500 W

Formula: kWh = watts × hours per day × days ÷ 1,000; cost = kWh × electricity rate.

Inputs used: device: space heater; power: 1,500 W; use: 8 h/day; rate: 18.16¢/kWh.

These are estimates, not financial advice.

Source: U.S. Energy Information Administration (Aug 2026). About our data

Worked examples in three states

8 hours a day for 30 days at each state’s August 2026 average price.

StatePrice1,500 W heater8,000 Btu/h AC
Hawaii47.18¢/kWh$169.85$82.35
Alabama16.33¢/kWh$58.79$28.50
Nevada12.72¢/kWh$45.79$22.20

Source: U.S. Energy Information Administration (Aug 2026). About our data

How we calculate

AC power (W) = Btu/h ÷ EER; kWh = watts × hours × days ÷ 1,000; cost = kWh × price. Prices: EIA average residential price by state. Device sizes and the 8-hour day are examples; see the methodology.

Frequently asked questions

How much does a 1,500 W space heater cost per hour?

It uses 1.5 kWh per hour at full power, so at the U.S. average of 18.16¢/kWh (August 2026) it costs about $0.27 an hour. Thermostats cycle the heater, so actual running time is usually less than the time it is switched on.

How do I find my air conditioner’s power use?

Divide its cooling capacity (Btu/h) by its EER or CEER from the EnergyGuide label. An 8,000 Btu/h unit with an EER of 11 draws about 727 W while the compressor runs.

Is a space heater cheaper than central heating?

Heating one small room with a space heater can cost less than heating the whole house, but per unit of heat, electric resistance heat is usually more expensive than a heat pump and often more expensive than gas. Compare options with the heat pump vs gas furnace calculator.

Data last updated: