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How much does it cost to run a window air conditioner?
At the U.S. average residential price of 18.16¢ per kilowatt-hour (August 2026), running a window air conditioner costs about $126 a year. Your own bill depends on your state's rate, which ranges from 12.72¢ to 47.18¢ across the country.
- Per hour
- 13.1¢
- Per day of use
- $1.05
- Per month
- $10.46
- Per year
- $126
Assumption: 900 W at a 80% duty cycle, 8 hours a day, 120 days a year — 691 kWh a year. Typical of a 10,000 BTU window unit. Small 5,000 BTU units draw closer to 500 W; 15,000 BTU units closer to 1,400 W.
Cost by state
Same appliance, same usage, 51 different prices. Sorted cheapest first.
| State | Rate | Per month | Per year |
|---|---|---|---|
| Nevada | 12.72¢ | $7.33 | $87.92 |
| Louisiana | 12.87¢ | $7.41 | $88.96 |
| North Dakota | 13.31¢ | $7.67 | $92.00 |
| Utah | 13.31¢ | $7.67 | $92.00 |
| Idaho | 13.37¢ | $7.70 | $92.41 |
| Tennessee | 13.42¢ | $7.73 | $92.76 |
| Nebraska | 13.54¢ | $7.80 | $93.59 |
| Kentucky | 13.80¢ | $7.95 | $95.39 |
| Arkansas | 14.37¢ | $8.28 | $99.33 |
| Mississippi | 14.43¢ | $8.31 | $99.74 |
| Wyoming | 14.43¢ | $8.31 | $99.74 |
| Washington | 14.63¢ | $8.43 | $101 |
| Oklahoma | 14.82¢ | $8.54 | $102 |
| North Carolina | 14.95¢ | $8.61 | $103 |
| Florida | 14.99¢ | $8.63 | $104 |
| Arizona | 15.05¢ | $8.67 | $104 |
| South Dakota | 15.15¢ | $8.73 | $105 |
| Kansas | 15.47¢ | $8.91 | $107 |
| Montana | 15.57¢ | $8.97 | $108 |
| South Carolina | 15.76¢ | $9.08 | $109 |
| Georgia | 15.90¢ | $9.16 | $110 |
| Texas | 15.91¢ | $9.16 | $110 |
| Oregon | 15.92¢ | $9.17 | $110 |
| Missouri | 16.02¢ | $9.23 | $111 |
| West Virginia | 16.31¢ | $9.39 | $113 |
| Alabama | 16.33¢ | $9.41 | $113 |
| New Mexico | 16.51¢ | $9.51 | $114 |
| Indiana | 17.02¢ | $9.80 | $118 |
| Iowa | 17.06¢ | $9.83 | $118 |
| Colorado | 17.17¢ | $9.89 | $119 |
| Minnesota | 17.20¢ | $9.91 | $119 |
| Virginia | 17.64¢ | $10.16 | $122 |
| Delaware | 18.70¢ | $10.77 | $129 |
| Illinois | 19.32¢ | $11.13 | $134 |
| Ohio | 19.38¢ | $11.16 | $134 |
| Wisconsin | 19.41¢ | $11.18 | $134 |
| Maryland | 21.40¢ | $12.33 | $148 |
| Pennsylvania | 21.77¢ | $12.54 | $150 |
| Michigan | 22.99¢ | $13.24 | $159 |
| Vermont | 23.84¢ | $13.73 | $165 |
| Connecticut | 24.51¢ | $14.12 | $169 |
| New Jersey | 24.61¢ | $14.18 | $170 |
| District of Columbia | 25.98¢ | $14.96 | $180 |
| New Hampshire | 27.64¢ | $15.92 | $191 |
| Rhode Island | 28.18¢ | $16.23 | $195 |
| New York | 28.65¢ | $16.50 | $198 |
| Alaska | 29.41¢ | $16.94 | $203 |
| California | 29.75¢ | $17.14 | $206 |
| Massachusetts | 30.48¢ | $17.56 | $211 |
| Maine | 32.11¢ | $18.50 | $222 |
| Hawaii | 47.18¢ | $27.18 | $326 |
Cutting the number down
- Sealing the gaps around the sleeve with foam matters more than the unit's efficiency rating. Warm air leaking back in is load you pay to remove twice.
- An inverter model modulates instead of slamming on and off, which shows up as a lower effective duty cycle rather than a lower nameplate watt.
- Shading the outdoor half of the unit lowers the temperature it rejects heat into, which lowers the work it has to do.
Questions
- How many watts does a window air conditioner use?
- About 900 W while running, though it cycles on and off, so average draw is 720 W.
- How much does a window air conditioner cost per month?
- About $10.46 a month at the U.S. average rate, or $126 a year.
- Where is it cheapest to run?
- Nevada, at $87.92 a year, versus $326 in Hawaii — a spread of $238.