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How much does it cost to run a window AC?

A window AC draws 397–1,200 watts while it cools, depending on its size. A 10,000–14,000 BTU unit uses about 4.50 kilowatt-hours (kWh) in 6 hours.

What do you run?

Tap a row to edit it.

  • Size
    watts
    Hours a dayHours a day
    How manyHow many
    When

    750 W × 6 hours = 4.50 kWh a day · × 30.4 days = 136.8 kWh × 18.0¢ US average = $24.62 a summer month

    A kilowatt-hour (kWh) is 1,000 watts for one hour. It’s what your bill counts.

$25a summer month

$25 a summer month

At 4 hours a day, it’s about $16.42 a summer month.

Estimate my billSee prices by state

How much power does each size of window AC use?

Bigger units use more. One of 14,000 BTU and up draws about 3 times as much as one under 7,000 BTU.

  • Under 7,000 BTU397 W · 2.38 kWh a day$13.03
  • 7,000–10,000 BTU533 W · 3.20 kWh a day$17.51
  • 10,000–14,000 BTU750 W · 4.50 kWh a day$24.62
  • 14,000 BTU and up1,200 W · 7.20 kWh a day$39.40

ENERGY STAR · certified models · pulled Nov 3, 2026

Each row is the middle (median) ENERGY STAR model of its size. Watts are each unit’s cooling capacity (BTU) ÷ its efficiency rating (CEER).

What does a window AC cost to run in each state?

The same window AC costs more than three times as much in Hawaii as in North Dakota.

  1. Hawaii$60.60 · 44.3¢
  2. California$44.19 · 32.3¢
  3. Massachusetts$41.59 · 30.4¢
  4. Maine$40.49 · 29.6¢
  5. Rhode Island$40.22 · 29.4¢
  6. US average$24.62 · 18.0¢
  7. Idaho$17.51 · 12.8¢
  8. Nebraska$17.37 · 12.7¢
  9. North Dakota$16.83 · 12.3¢
See prices by state

A 10,000–14,000 BTU window AC (750 W for 6 hours a day) at each state’s average price.

State averages · last 12 months · US government data (EIA)

More for heating and cooling

FAQ

Questions about window AC power

The middle ENERGY STAR 10,000–14,000 BTU window AC draws about 750 watts, so 6 hours a day uses about 4.50 kWh. Across sizes, the range is 397–1,200 watts. A kilowatt-hour (kWh) is 1,000 watts for one hour.

Information as of Nov 2, 2026.

Our numbers come from US government data (EIA) and ENERGY STAR.

Window AC figures: ENERGY STAR Certified Room Air Conditioners (opens data.energystar.gov in a new tab) (pulled Nov 3, 2026); DOE test procedure, 10 CFR 430 subpart B, appendix F (opens www.ecfr.gov in a new tab).

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