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How Much Does It Cost to Run a Window Air Conditioner? $20/Month

Running a window air conditioner at 1,100 watts for 3.6 hours a day costs about $0.67 a day and $20.20 a month at 17¢/kWh, the EIA 2025 annual US average (July 2026 monthly: 18.31¢) — roughly $101 a year.

1,100 W (500–1,500 W)Typical power draw
3.6 h/day, 30 days/monthAssumed use
3.96 kWhEnergy per day

· Source: EIA Electric Power Monthly Table 5.6.A (July 2026 data) · next EIA update ~Oct 23

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a window air conditioner: energy cost only (1,100 W ÷ 1,000 × hours × rate); fixed fees and taxes extra.
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Slider nudges the rate for a window air conditioner; the URL keeps it.

## How much does it cost to run a window air conditioner?

The same a window air conditioner at 3.6 hours a day costs $14.26 a month at 12¢ and $53.46 at 45¢ — usage held constant, only the rate moving:

Table 1: How Much Does It Cost to Run a Window Air Conditioner? $20/Month
Electricity rate Per hour Per day Per month in season Per year
12¢/kWh $0.132 $0.48 $14.26 $71
15¢/kWh $0.165 $0.59 $17.82 $89
17¢/kWh (US avg) $0.187 $0.67 $20.20 $101
20¢/kWh $0.220 $0.79 $23.76 $119
25¢/kWh $0.275 $0.99 $29.70 $149
30¢/kWh $0.330 $1.19 $35.64 $178
35¢/kWh $0.385 $1.39 $41.58 $208
45¢/kWh $0.495 $1.78 $53.46 $267
Typical power draw
1,100 W (500–1,500 W)
Assumed use
3.6 h/day, 30 days/month
Energy per day
3.96 kWh
Cost per day
$0.67
Cost per month
$20.20
Cost per year
$101

Why this number

Running a window air conditioner at 1,100 watts for 3.6 hours a day costs about $0.67 a day and $20.20 a month at 17¢/kWh, the EIA 2025 annual US average (July 2026 monthly: 18.31¢) — roughly $101 a year. The formula for a window air conditioner: 1,100 W ÷ 1,000 × hours × your rate per kWh. For a window air conditioner your own rate changes the answer: at 12¢/kWh that month costs $14.26, at 45¢/kWh it costs $53.46.

A window air conditioner rated at 1,100 watts, run 3.6 hours a day, costs about $0.67 a day — about $20.20 a month, or $101 a year — at the US average electricity rate of 17¢/kWh. That places it 18th of the 40 appliances tracked here — mid-table, but high enough that it is worth being deliberate about how much you use it.

What actually drives this number

A window unit’s advantage is not efficiency but zoning: cooling one occupied room instead of a whole house. Against central air it usually wins for a single room and loses badly if you put one in every room and run them all.

Unlike resistance loads, efficiency here is genuinely shoppable — the CEER rating on the EnergyGuide label sets the input watts directly, and it is a large part of why real units span 500–1,500 W. The same refrigeration cycle also runs in reverse: the heat pump , at about $104.78 an in-season month, is what that trick looks like applied to heating.

Where this number comes from

Putting Window air conditioner in proportion

At 17¢/kWh, a window air conditioner next to the rest of the bill:

For a window air conditioner: cooling equipment moves heat rather than making it, so it delivers several units of cooling per unit of electricity. That efficiency is why it beats resistance heating for the same effect, and long run-hours are why it still lands high on the bill. On this site’s own numbers, a window air conditioner lands at #18 of 40 on the monthly-cost ranking, at about $20.20 for a typical month.

The formula, in full

The 1,100 W arithmetic for a window air conditioner, step by step:

  1. Watts to kilowatts. 1,100 W ÷ 1,000 = 1.10 kW.
  2. Energy per day. 1.10 kW × 3.6 hours = 3.96 kWh.
  3. Cost per day. 3.96 kWh × $0.17 = $0.67.
  4. Cost per month. $0.67 × 30 days = $20.20.

For a window air conditioner the two levers are run-hours (3.6 h/day here) and your rate; at 3.6 hours a day, 1,100 W adds up — which is why cooling equipment dominate the rankings.

Window air conditioner running cost by state

Hours and rate both change with geography: the state pages scale the 3.6 h/day baseline by each state’s degree-days and price it at the state’s own EIA rate and its largest utilities’ prices. Cold states so far: Alaska , Colorado , Connecticut , Idaho , Illinois , Iowa , Maine , Massachusetts , Michigan , Minnesota , Montana , Nebraska , New Hampshire , New York , North Dakota , South Dakota , Utah , Vermont , Wisconsin , Wyoming .

Other cooling loads: Heat pump water heater ($169/yr), Ceiling fan ($11/yr), Portable air conditioner ($233/yr). Closest on annual cost: Dehumidifier ($122/yr), Clothes dryer ($79/yr). Across all other cooling loads here, the priciest is Heat pump at $104.78/mo.

The a window air conditioner table above runs a fixed rate ladder (12–45¢); the state quick-fill uses July 2026 averages from EIA Electric Power Monthly, Table 5.6.A .

Put a window air conditioner ($20.20 a month) against everything else in the electricity cost calculator , check your state’s rate , or browse all 40 appliances ; year-round high bills: solar savings calculator .

Frequently asked questions

How much does it cost to run a window air conditioner per hour?

About $0.187 an hour for a window air conditioner at 17¢/kWh, the EIA 2025 annual US average (July 2026 monthly: 18.31¢), for a 1,100 W unit. The calculation is 1,100 ÷ 1,000 × 1 hour × $0.17 per kWh. At 30¢/kWh the same hour costs $0.330.

How much does a window air conditioner add to my monthly bill?

Roughly $20.20 a month for a window air conditioner at 3.6 hours a day, 30 days a month, 17¢/kWh. That is about $101 a year across a 5-month season. For a window air conditioner, change the 3.6-hour default to your own use — run-time moves the total as much as the 1,100 W does.

How many watts does a window air conditioner use?

Typically around 1,100 W, with real units ranging from about 500 to 1,500 W depending on size, model and setting. The nameplate on your own unit is the figure to trust — these are typical values for planning, not a measurement of your appliance.

Why is my actual bill higher than the a window air conditioner figure?

$20.20 a month is the energy cost of a window air conditioner alone; your bill adds fixed connection charges, delivery fees, taxes and every other load. Add the other appliances in the index to a window air conditioner for the controllable part of the bill.

How we calculated this

Worked for a window air conditioner: 1,100 W ÷ 1,000 × 3.6 h × $0.17 = $0.67 a day; × 30 days = $20.20 a month; × 5 months in use = $101 a year. 1,100 W and 3.6 h are the typical figures cited for a window air conditioner; 17¢ is EIA’s 2025 annual US average.

Sources: U.S. Energy Information Administration (EIA) electricity rates · DSIRE incentive records · public IRS/OBBBA guidance. Figures are modeled estimates, not quotes or tax advice. See our methodology.

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