Window air conditioner: electricity cost calculator
Quick answer: a typical window air conditioner costs about $40/month while in use at the U.S. average electricity price (18.44¢/kWh) across a 4-month season (about $162/year). Your number depends on wattage, runtime and your state — calculate it below.
Most 8,000–12,000 BTU window units draw 700–1,100 W while cooling. The preset assumes 8 hours of compressor runtime on a warm day across a 4-month season.
7.20 kWh/day used · 219 kWh/month in use · 877 kWh/year at 18.44¢ per kWh (4 months of use per year)
Typical running watts by unit size
Monthly cost assumes the preset 8 h/day at the U.S. average price of 18.44¢/kWh — enter your size's wattage in the calculator above for exact numbers.
| Size | Running watts | Per month in use |
|---|---|---|
| 5,000 BTU (small bedroom) | ~450 W | $20 |
| 8,000 BTU (bedroom) | ~700 W | $31 |
| 10,000 BTU (large room) | ~900 W | $40 |
| 12,000 BTU (living room) | ~1,100 W | $49 |
| 15,000 BTU (open space) | ~1,400 W | $63 |
Low, typical and heavy use
Monthly cost while in use, at the U.S. average price of 18.44¢/kWh.
| Scenario | Watts | Hours/day | Per month |
|---|---|---|---|
| Light use | 600 W | 4.8 h | $16.16 |
| Typical | 900 W | 8.0 h | $40.41 |
| Heavy use | 1,400 W | 12.0 h | $94.29 |
Common questions
How much does a window AC cost to run overnight?
At the preset 900 W and the U.S. average price, 8 hours overnight costs roughly $1.30. Use your state's average or your exact bill rate above for a precise figure.
Is eco mode worth using?
Eco mode cycles the compressor and fan off once the room reaches temperature, often cutting runtime 10–30% with little comfort loss.
Cost in every state
Monthly cost of a typical window air conditioner (900 W, 8h/day) at each state's average residential price, May 2026.
| State | Avg price | Per month |
|---|---|---|
| Alabama | 16.77¢ | $36.75 |
| Alaska | 28.23¢ | $61.87 |
| Arizona | 15.23¢ | $33.38 |
| Arkansas | 14.36¢ | $31.47 |
| California | 33.25¢ | $72.87 |
| Colorado | 16.16¢ | $35.41 |
| Connecticut | 27.37¢ | $59.98 |
| Delaware | 19.38¢ | $42.47 |
| District of Columbia | 25.40¢ | $55.66 |
| Florida | 15.17¢ | $33.25 |
| Georgia | 15.84¢ | $34.71 |
| Hawaii | 52.00¢ | $113.96 |
| Idaho | 12.35¢ | $27.07 |
| Illinois | 23.85¢ | $52.27 |
| Indiana | 18.15¢ | $39.78 |
| Iowa | 14.14¢ | $30.99 |
| Kansas | 15.13¢ | $33.16 |
| Kentucky | 14.98¢ | $32.83 |
| Louisiana | 14.15¢ | $31.01 |
| Maine | 28.63¢ | $62.74 |
| Maryland | 21.77¢ | $47.71 |
| Massachusetts | 28.82¢ | $63.16 |
| Michigan | 22.01¢ | $48.23 |
| Minnesota | 16.95¢ | $37.15 |
| Mississippi | 16.16¢ | $35.41 |
| Missouri | 13.68¢ | $29.98 |
| Montana | 14.67¢ | $32.15 |
| Nebraska | 13.59¢ | $29.78 |
| Nevada | 13.60¢ | $29.80 |
| New Hampshire | 27.33¢ | $59.89 |
| New Jersey | 23.27¢ | $51.00 |
| New Mexico | 14.12¢ | $30.94 |
| New York | 29.93¢ | $65.59 |
| North Carolina | 15.09¢ | $33.07 |
| North Dakota | 13.61¢ | $29.83 |
| Ohio | 19.52¢ | $42.78 |
| Oklahoma | 13.38¢ | $29.32 |
| Oregon | 16.27¢ | $35.66 |
| Pennsylvania | 21.55¢ | $47.23 |
| Rhode Island | 29.46¢ | $64.56 |
| South Carolina | 16.18¢ | $35.46 |
| South Dakota | 15.73¢ | $34.47 |
| Tennessee | 14.47¢ | $31.71 |
| Texas | 16.44¢ | $36.03 |
| Utah | 12.96¢ | $28.40 |
| Vermont | 24.89¢ | $54.55 |
| Virginia | 17.61¢ | $38.59 |
| Washington | 14.95¢ | $32.76 |
| West Virginia | 16.80¢ | $36.82 |
| Wisconsin | 19.74¢ | $43.26 |
| Wyoming | 14.80¢ | $32.43 |
Related calculators
Central air conditioner The biggest single line on most summer power bills.
~3,500 W · 8h/day →
Portable air conditioner Convenient, but the least efficient way to cool a room.
~1,100 W · 8h/day →
Ductless mini-split Inverter compressors sip power once the room is at temperature.
~800 W · 8h/day →
Central heat pump Heats and cools — usually the cheapest electric heat available.
~3,000 W · 6h/day →
Space heater 1,500 watts adds up faster than most people expect.
~1,500 W · 6h/day →
Electric baseboard heater Simple, silent, and one of the priciest ways to heat.
~1,500 W · 8h/day →
Methodology & sources
Cost = watts ÷ 1,000 × hours × price per kWh. Electricity prices are average residential prices by state from the EIA Electric Power Monthly, Table 5.6.A (May 2026). EIA averages include delivery charges and taxes but are not any specific utility tariff — for an exact figure, use the rate from your own bill. Wattage presets reflect common product ranges; check your appliance's nameplate or a plug-in power meter for its true draw.
Last verified: July 30, 2026. Prices refresh automatically each month when EIA publishes new data.