How much does a window ac unit cost to run?
Updated August 2026 · average residential rates
Quick answer: a window ac unit (500–1,400 W depending on BTU size) costs about 11.4¢ per hour to run at the US average rate. With 8 hours/day in summer, that's 91.3¢/day, $27.74/month and $333/year — using ~5.4 kWh a day. Your state's rate can move this from $18.39 to $69.11 monthly.
Run your own numbers
500–1,400 W depending on BTU size · default assumes 8 hours/day in summer · compressor duty cycle ~75% factored in
Uses about 5.4 kWh/day at 15.6¢/kWh (Texas). National average would be $27.74/month.
Window AC Unit cost by state
| State | Rate | Per hour | Per month |
|---|---|---|---|
| Alabama | 15.6¢/kWh | 10.5¢ | $25.61 |
| Alaska | 24.9¢/kWh | 16.8¢ | $40.88 |
| Arizona | 15.2¢/kWh | 10.3¢ | $24.95 |
| Arkansas | 12.7¢/kWh | 8.6¢ | $20.85 |
| California | 31.8¢/kWh | 21.5¢ | $52.20 |
| Colorado | 15.3¢/kWh | 10.3¢ | $25.12 |
| Connecticut | 32.3¢/kWh | 21.8¢ | $53.02 |
| Delaware | 16.8¢/kWh | 11.3¢ | $27.58 |
| District of Columbia | 17.6¢/kWh | 11.9¢ | $28.89 |
| Florida | 15.1¢/kWh | 10.2¢ | $24.79 |
| Georgia | 14.2¢/kWh | 9.6¢ | $23.31 |
| Hawaii | 42.1¢/kWh | 28.4¢ | $69.11 |
| Idaho | 11.6¢/kWh | 7.8¢ | $19.04 |
| Illinois | 16.4¢/kWh | 11.1¢ | $26.92 |
| Indiana | 15.7¢/kWh | 10.6¢ | $25.77 |
| Iowa | 13.7¢/kWh | 9.2¢ | $22.49 |
| Kansas | 14.3¢/kWh | 9.7¢ | $23.47 |
| Kentucky | 13.1¢/kWh | 8.8¢ | $21.50 |
| Louisiana | 12.1¢/kWh | 8.2¢ | $19.86 |
| Maine | 25.6¢/kWh | 17.3¢ | $42.02 |
| Maryland | 18.1¢/kWh | 12.2¢ | $29.71 |
| Massachusetts | 31.2¢/kWh | 21.1¢ | $51.22 |
| Michigan | 19.4¢/kWh | 13.1¢ | $31.85 |
| Minnesota | 15.1¢/kWh | 10.2¢ | $24.79 |
| Mississippi | 13.6¢/kWh | 9.2¢ | $22.33 |
| Missouri | 12.6¢/kWh | 8.5¢ | $20.68 |
| Montana | 12.8¢/kWh | 8.6¢ | $21.01 |
| Nebraska | 12.1¢/kWh | 8.2¢ | $19.86 |
| Nevada | 15.4¢/kWh | 10.4¢ | $25.28 |
| New Hampshire | 25.2¢/kWh | 17.0¢ | $41.37 |
| New Jersey | 19.6¢/kWh | 13.2¢ | $32.18 |
| New Mexico | 14.6¢/kWh | 9.9¢ | $23.97 |
| New York | 24.6¢/kWh | 16.6¢ | $40.38 |
| North Carolina | 14.1¢/kWh | 9.5¢ | $23.15 |
| North Dakota | 11.2¢/kWh | 7.6¢ | $18.39 |
| Ohio | 16.3¢/kWh | 11.0¢ | $26.76 |
| Oklahoma | 12.2¢/kWh | 8.2¢ | $20.03 |
| Oregon | 14.8¢/kWh | 10.0¢ | $24.30 |
| Pennsylvania | 18.4¢/kWh | 12.4¢ | $30.21 |
| Rhode Island | 30.4¢/kWh | 20.5¢ | $49.90 |
| South Carolina | 14.7¢/kWh | 9.9¢ | $24.13 |
| South Dakota | 12.6¢/kWh | 8.5¢ | $20.68 |
| Tennessee | 13.2¢/kWh | 8.9¢ | $21.67 |
| Texas | 15.6¢/kWh | 10.5¢ | $25.61 |
| Utah | 11.7¢/kWh | 7.9¢ | $19.21 |
| Vermont | 21.6¢/kWh | 14.6¢ | $35.46 |
| Virginia | 14.6¢/kWh | 9.9¢ | $23.97 |
| Washington | 12.3¢/kWh | 8.3¢ | $20.19 |
| West Virginia | 14.8¢/kWh | 10.0¢ | $24.30 |
| Wisconsin | 17.2¢/kWh | 11.6¢ | $28.24 |
| Wyoming | 11.8¢/kWh | 8.0¢ | $19.37 |
FAQ
How much electricity does a window ac unit use?+
A typical window ac unit draws 500–1,400 W depending on BTU size. At 8 hours/day in summer (with a ~75% duty cycle), that's about 5.4 kWh per day.
How much does a window ac unit cost to run per month?+
About $27.74 per month at the US average residential rate of 16.9¢/kWh — ranging from roughly $18.39 in North Dakota to $69.11 in Hawaii.
Is it expensive to leave a window ac unit on?+
Running it costs about 11.4¢ per hour at average rates. Multiply by your actual hours — and check your state's rate above, since electricity prices vary almost 4× across the US.