hvac · 900W typical
Running a window air conditioner costs about $21.38/month.
That's the typical window air conditioner at 900W, run 8 hours a day at the US-average rate of 16.5¢/kWh. Change any of those and the number moves — use the calculator below to see yours.
Estimated cost
A window air conditioner draws full power only while the thermostat/compressor is running — about 4.8 effective hours at 900W across your 8-hour window.
How you use it
Cost shifts with how long it's on.
The same window air conditioner can cost very different amounts depending on usage patterns. Three common scenarios, at the US-average rate.
single bedroom
$21.38
per month
bedroom AC run overnight plus a few evening hours
living room daytime
$26.73
per month
primary cooling for an apartment during summer
heatwave
$37.42
per month
running nearly continuously during extreme heat
Where you live
$38.75 spread between the cheapest and priciest states.
Same appliance, same hours of use, different zip code — the monthly cost varies this much.
| State | Rate | Monthly | Yearly |
|---|---|---|---|
| Hawaii | 41.2¢ | $53.40 | $649.64 |
| California | 31.4¢ | $40.69 | $495.12 |
| Massachusetts | 30.8¢ | $39.92 | $485.65 |
| Connecticut | 28.7¢ | $37.20 | $452.54 |
| Rhode Island | 27.9¢ | $36.16 | $439.93 |
| New Hampshire | 24.6¢ | $31.88 | $387.89 |
| Alaska | 24.3¢ | $31.49 | $383.16 |
| New York | 22.3¢ | $28.90 | $351.63 |
| Maine | 22.1¢ | $28.64 | $348.47 |
| Vermont | 21.5¢ | $27.86 | $339.01 |
| Michigan | 19.3¢ | $25.01 | $304.32 |
| New Jersey | 19.1¢ | $24.75 | $301.17 |
| Maryland | 18.4¢ | $23.85 | $290.13 |
| Pennsylvania | 18.1¢ | $23.46 | $285.40 |
| District of Columbia | 17.8¢ | $23.07 | $280.67 |
| Wisconsin | 17.4¢ | $22.55 | $274.36 |
| Delaware | 17.2¢ | $22.29 | $271.21 |
| Illinois | 16.9¢ | $21.90 | $266.48 |
| Ohio | 16.6¢ | $21.51 | $261.75 |
| Nevada | 16.3¢ | $21.12 | $257.02 |
| Indiana | 15.8¢ | $20.48 | $249.13 |
| Virginia | 15.7¢ | $20.35 | $247.56 |
| Minnesota | 15.6¢ | $20.22 | $245.98 |
| Colorado | 15.4¢ | $19.96 | $242.83 |
| Alabama | 15.2¢ | $19.70 | $239.67 |
| West Virginia | 15.2¢ | $19.70 | $239.67 |
| Florida | 15.1¢ | $19.57 | $238.10 |
| New Mexico | 14.8¢ | $19.18 | $233.37 |
| Texas | 14.8¢ | $19.18 | $233.37 |
| Arizona | 14.7¢ | $19.05 | $231.79 |
| South Carolina | 14.7¢ | $19.05 | $231.79 |
| Kansas | 14.6¢ | $18.92 | $230.21 |
| Georgia | 14.2¢ | $18.40 | $223.91 |
| Iowa | 14.1¢ | $18.27 | $222.33 |
| North Carolina | 13.9¢ | $18.01 | $219.18 |
| Missouri | 13.6¢ | $17.63 | $214.44 |
| Oregon | 13.4¢ | $17.37 | $211.29 |
| Tennessee | 13.3¢ | $17.24 | $209.71 |
| Kentucky | 13.2¢ | $17.11 | $208.14 |
| Mississippi | 13.1¢ | $16.98 | $206.56 |
| Oklahoma | 13.1¢ | $16.98 | $206.56 |
| South Dakota | 12.7¢ | $16.46 | $200.25 |
| Montana | 12.4¢ | $16.07 | $195.52 |
| Nebraska | 12.2¢ | $15.81 | $192.37 |
| Arkansas | 12.1¢ | $15.68 | $190.79 |
| Washington | 12.1¢ | $15.68 | $190.79 |
| Louisiana | 11.9¢ | $15.42 | $187.64 |
| Wyoming | 11.6¢ | $15.03 | $182.91 |
| North Dakota | 11.5¢ | $14.90 | $181.33 |
| Utah | 11.4¢ | $14.77 | $179.76 |
| Idaho | 11.3¢ | $14.64 | $178.18 |
Efficient vs. inefficient
A $185.01/year difference across the wattage range.
Swapping a high-draw model for an efficient one pays for itself. Here's what that looks like annually at typical usage.
Most efficient
800W
$19.01 per month
$231.26 per year
Typical
900W
$21.38 per month
$260.17 per year
High draw
1440W
$34.21 per month
$416.28 per year
When it hits hardest
summer peak
June through September; most units sit idle the rest of the year.
Ways to cut the cost
- 1
Upgrade to an inverter (variable-speed) model when replacing
Cuts energy use 30-40% vs. single-stage window units
- 2
Seal around the unit with weatherstripping and insulation panels
Can reduce runtime 10-15% in leaky windows
- 3
Clean the filter monthly during cooling season
Restores 5-10% efficiency
Real-world wattages
Pulled from actual spec sheets.
| Brand | Model | Watts |
|---|---|---|
| LG | LW8017ERSM (8,000 BTU) | 715W |
| Frigidaire | FFRE103WAE (10,000 BTU) | 900W |
| Midea | U MAW08V1QWT (8,000 BTU) | 700W |
Picks that actually move the needle
Three products worth comparing if you're thinking about upgrading or supplementing what you have.
Some links below are affiliate links. If you buy, we may earn a small commission — it never changes the price you pay, and we only recommend picks we would stand behind.
See also
Related appliances
Sources: www.energystar.gov · www.energy.gov
Last updated: 2026-04-13