Cost to run a window air conditioner
Heating & cooling · typical wattage 900 W (500 W-1,400 W)
A window air conditioner draws about 500 W-1,400 W (typically 900 W). Run 8 hours a day, it uses about 864 kWh/year, which costs roughly $13.36/month and $160/year at the US average residential rate of 18.56¢/kWh (March 2026). At a high-rate state like California (33.35¢) it costs more; at a low-rate state like Washington (14.40¢) it costs less.
Source: U.S. DOE — Estimating Appliance and Home Electronic Energy Use. Data as of June 2026.
Window air conditioner at a glance
| Figure | Window air conditioner |
|---|---|
| Typical running wattage | 900 W (500 W-1,400 W) |
| Assumed usage | 8 h/day, 120 days/yr |
| Energy used | 864 kWh per year |
| Cost per month @ 18.56¢ | $13.36 |
| Cost per year @ 18.56¢ | $160 |
Source: U.S. DOE — Estimating Appliance and Home Electronic Energy Use; ENERGY STAR product specifications. Data as of June 2026.
Cost at light, typical and heavy use
How the monthly and yearly cost changes with how long you run it, at the US average 18.56¢/kWh:
| Usage | Cost / month | Cost / year |
|---|---|---|
| Light use (4 h/day) | $20.04 | $244 |
| Typical use (8 h/day) | $40.09 | $488 |
| Heavy use (12 h/day) | $60.13 | $732 |
Cost at different state rates
The same window air conditioner at typical usage, priced at a few representative state rates:
| Rate | Cost / month | Cost / year |
|---|---|---|
| US average (18.56¢) | $13.36 | $160 |
| Washington (14.40¢) | $31.10 | $378 |
| Texas (16.39¢) | $35.40 | $431 |
| California (33.35¢) | $72.04 | $876 |
Source: EIA Electric Power Monthly, Table 5.6.A (residential) (March 2026). Data as of June 2026.
Use the calculator to price it at your exact rate, or see all 51 states.
Wattage source & how to save
Window units range from about 500 W (small 5,000 BTU) to 1,400 W (large 12,000+ BTU).
Tip to cut the cost: Pick an ENERGY STAR unit sized to the room and seal the window to stop warm-air leaks.
Frequently asked questions
How much does it cost to run a window air conditioner?
At the US average residential rate of 18.56¢/kWh, a window air conditioner (about 500 W-1,400 W, typically 900 W) used 8 hours a day costs roughly $13.36 per month and $160 per year. Your cost depends on your exact wattage, usage and local rate. Use the calculator for an exact figure.
How many watts does a window air conditioner use?
Window units range from about 500 W (small 5,000 BTU) to 1,400 W (large 12,000+ BTU).
How much electricity does a window air conditioner use per year?
About 864 kWh per year at typical usage. That's 7.20 kWh per day at 8 hours of use.
How can I cut the running cost of a window air conditioner?
Pick an ENERGY STAR unit sized to the room and seal the window to stop warm-air leaks.
Keep exploring
Sources & accuracy
Wattage: U.S. DOE — Estimating Appliance and Home Electronic Energy Use and ENERGY STAR-grade references (typical figures; ranges shown where relevant). Electricity rate: EIA Electric Power Monthly (March 2026). All public domain. Costs are a transparent calculation (see methodology) and are estimates only — your appliance's actual wattage, your usage and your utility rate may differ. Check the appliance label and your bill before relying on these figures.
Last updated: 2026-06-20