How Much Does It Cost to Run a Window Air Conditioner (12,000 BTU)?
Short answer: about $0.91 a day and $27.40 a month, or $0.19 for each hour it runs at full power, at the 2025 US average electricity rate. That is for a 1,100 W window air conditioner (12,000 btu) running 8 hours a day with a 60% duty cycle. Change the state and hours below for your own number.
Updated Nov 8, 2026
Quick answer
Quick answer, US average (17.3 c/kWh)
About $27.40 a month
The same use costs $18.71 a month in North Dakota and $64.29 in Hawaii.
- Per hour
- $0.11
- with 60% cycling; $0.19 at full 1,100 W
- Per day
- $0.91
- 8 h, 5.28 kWh
- Per month
- $27.40
- 30 days
- Per year
- $333.41
- 365 days at the same use
Your state, your hours
Per hour
$0.11
Per day
$0.91
Per month
$27.40
Per year
$333.41
Window Air Conditioner (12,000 BTU) at 1,100 W, 8 h a day, 30 days a month, 60% duty cycle: 158.4 kWh a month. Using the 2025 US average of 17.3 cents/kWh.
Want to change the watts or duty cycle too? Open the full calculator.
What decides the cost of running a window air conditioner (12,000 btu)
A 12,000 BTU window unit is one ton of cooling, enough for a 450 to 550 square foot room, a large living room or a small apartment's main space. While the compressor runs, a current 115 V model draws about 1,000 to 1,200 W, around 9 to 10 A, and needs a 15 or 20 A outlet with little else on the circuit. The default here is 1,100 W for 8 hours at a 60 percent duty cycle, about 5.3 kWh a day, roughly 91 cents at the national average rate.
Efficiency is printed on the box as the CEER, BTU per hour of cooling divided by watts. Dividing 12,000 by the CEER gives a rough average draw. A unit rated CEER 10.8 averages about 1,110 W, and an inverter model rated CEER 15 about 800 W, roughly 28 percent less for the same cooling. Inverter units also slow the compressor down once the room is cool instead of cycling it on and off, which is quieter and holds humidity lower.
The duty cycle depends on the room and the weather more than the unit. A well shaded room on an 85 degree day might keep the compressor running half the time, while a west-facing room with big windows on a 100 degree afternoon can keep it on continuously, which pushes the cost toward $1.52 for 8 hours. A unit that is too small for the room never catches up and runs constantly. One that is too large cools quickly, short-cycles and leaves the room clammy.
Against a central system, one or two window units are usually the cheaper way to cool a home where people spend most of their time in a few rooms. The default 3 ton central AC on this site uses about 14 kWh a day, while a 12,000 BTU window unit uses about 5.3. Once you need three or more large window units, central air or a ductless heat pump starts to win.
Over a 4 month cooling season the default comes to about 634 kWh, roughly $110.
How to cut it
- Size it to the room. The AC BTU calculator matches BTU to square footage, sun and ceiling height.
- Seal the side panels with foam and close blinds on sunny windows during the afternoon.
- Clean the filter every two weeks in summer. A clogged filter cuts airflow and lengthens every cycle.
- Raise the setpoint a few degrees and add a fan. Moving air feels cooler for a fraction of the power.
Window Air Conditioner (12,000 BTU) cost by state
Monthly cost for 1,100 W, 8 h a day, 60% duty cycle, 30 days, sorted cheapest to most expensive. Pick your state above to highlight it.
| Rank | State | Cents/kWh | Per month |
|---|---|---|---|
| 1 | North Dakota | 11.81 | $18.71 |
| 2 | Idaho | 11.82 | $18.72 |
| 3 | Nebraska | 12.34 | $19.55 |
| 4 | Louisiana | 12.57 | $19.91 |
| 5 | Arkansas | 12.84 | $20.34 |
| 6 | Montana | 12.98 | $20.56 |
| 7 | Utah | 13.07 | $20.70 |
| 8 | Washington | 13.11 | $20.77 |
| 9 | Oklahoma | 13.12 | $20.78 |
| 10 | Nevada | 13.15 | $20.83 |
| 11 | Tennessee | 13.18 | $20.88 |
| 12 | Kentucky | 13.24 | $20.97 |
| 13 | South Dakota | 13.38 | $21.19 |
| 14 | Wyoming | 13.38 | $21.19 |
| 15 | Missouri | 13.49 | $21.37 |
| 16 | Iowa | 13.72 | $21.73 |
| 17 | North Carolina | 14.02 | $22.21 |
| 18 | Mississippi | 14.03 | $22.22 |
| 19 | Kansas | 14.56 | $23.06 |
| 20 | Georgia | 14.73 | $23.33 |
| 21 | South Carolina | 14.96 | $23.70 |
| 22 | New Mexico | 15.08 | $23.89 |
| 23 | Florida | 15.24 | $24.14 |
| 24 | Virginia | 15.28 | $24.20 |
| 25 | Arizona | 15.32 | $24.27 |
| 26 | Oregon | 15.37 | $24.35 |
| 27 | West Virginia | 15.41 | $24.41 |
| 28 | Texas | 15.47 | $24.50 |
| 29 | Minnesota | 15.82 | $25.06 |
| 30 | Colorado | 15.85 | $25.11 |
| 31 | Alabama | 16.10 | $25.50 |
| 32 | Indiana | 16.23 | $25.71 |
| 33 | Ohio | 16.96 | $26.86 |
| 34 | Delaware | 17.13 | $27.13 |
| 35 | Illinois | 17.69 | $28.02 |
| 36 | Wisconsin | 18.16 | $28.77 |
| 37 | Pennsylvania | 19.30 | $30.57 |
| 38 | Maryland | 19.48 | $30.86 |
| 39 | Michigan | 20.01 | $31.70 |
| 40 | District of Columbia | 21.94 | $34.75 |
| 41 | New Jersey | 22.63 | $35.85 |
| 42 | Vermont | 22.92 | $36.31 |
| 43 | New Hampshire | 24.56 | $38.90 |
| 44 | Alaska | 26.09 | $41.33 |
| 45 | New York | 26.39 | $41.80 |
| 46 | Maine | 27.78 | $44.00 |
| 47 | Connecticut | 29.38 | $46.54 |
| 48 | Rhode Island | 29.46 | $46.66 |
| 49 | Massachusetts | 30.48 | $48.28 |
| 50 | California | 32.54 | $51.54 |
| 51 | Hawaii | 40.59 | $64.29 |
Rates: U.S. Energy Information Administration, Form EIA-861, annual average residential price, 2025 (eia.gov). Full list on the electricity rates by state page.
Cheaper to run
The swap that cuts this bill the most, from the products we track. Specs come from the listing or the maker.
LG 12,000 BTU Dual Inverter Smart Window AC
- inverter
- 12,000 BTU
- CEER 15
- 115V
+1 moreFewer
- ENERGY STAR
A dual inverter 12,000 BTU unit with a CEER of 15 and ENERGY STAR certification, rated 1,020 W cooling. It slows the compressor down instead of cycling it. Covers up to 550 sq ft on 115V.
- About 1,020 watts, lowest of the 12,000 BTU units
- Dual inverter, CEER 15, Energy Star certified
- ThinQ Wi-Fi control
- Occupies the window while installed
$500 to $1,000, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
Some links pay us a commission; that does not decide what we show. Not lab tested. See our disclosure.
Measure it instead of estimating
P3 Kill A Watt P4400 Electricity Usage Monitor
Plugs in between the wall and any 120 V appliance and shows watts and accumulated kWh. The cheapest way to replace the estimate on this page with your own number.
Under $100, live price on Amazon
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Frequently asked questions
How much does it cost to run a 12,000 BTU window AC per hour?+
About 19 cents for each hour the compressor runs, since 1.1 kWh x $0.173 = $0.19. Averaged over an hour with the compressor cycling 60 percent of the time, it is about 11 cents an hour.
How much does it cost to run a 12,000 BTU AC per day?+
About 91 cents a day on the default of 8 hours at a 60 percent duty cycle: 1.1 kW x 8 x 0.6 = 5.28 kWh, and 5.28 x $0.173 is $0.91.
How much does it cost to run a 12,000 BTU window AC per month?+
About $27 a month: 5.28 kWh x 30 days = 158 kWh, and 158.4 x $0.173 is $27.40. In a high-rate state such as California or Massachusetts it can be $45 or more for the same use.
How much does it cost to run a 12,000 BTU AC 24 hours a day?+
About $2.74 a day at a 60 percent duty cycle: 1.1 kW x 24 x 0.6 = 15.84 kWh, and 15.84 x $0.173 is $2.74. That is about $82 over a 30 day month.
How many watts does a 12,000 BTU window AC use?+
About 1,000 to 1,200 W while the compressor runs, and up to about 3,300 W for a moment at start-up on a non-inverter model. Divide 12,000 by the unit's CEER for a rough average: CEER 15 is about 800 W, CEER 10.8 about 1,110 W.
Does a 12,000 BTU AC use a lot of electricity?+
A moderate amount. It draws about 9 to 10 A at 115 V and uses about 5.3 kWh on an 8 hour day at the default, about 634 kWh over a 4 month summer, roughly $110 at the national average rate.
How much more does a 12,000 BTU AC cost than an 8,000 BTU?+
About 29 cents a day more on this site's defaults: 5.28 kWh (91 cents) against 3.6 kWh (62 cents) for an 8,000 BTU unit. Buy the size the room needs, since an undersized unit runs constantly and can cost as much.
How much does it cost to run a window AC all night?+
About 91 cents for 8 hours at a 60 percent duty cycle. At night the room usually cools faster, so the compressor often runs less and the real cost is lower, especially with a sleep mode that raises the setpoint.
Can a generator run a 12,000 BTU window AC?+
Yes, a generator with at least about 3,300 W of starting power, or less for an inverter AC with a soft start. It runs at about 1,100 W, so a 3,500 W inverter generator can carry it plus a fridge and lights. See the generator sizer.
How can I lower the cost of running a 12,000 BTU window AC?+
Seal the side panels, shade the window, clean the filter, and raise the setpoint with a fan running. When replacing, an ENERGY STAR inverter model at CEER 15 averages about 800 W against about 1,110 W for a CEER 10.8 unit, roughly 28 percent less.
Marcus Reed
Founder and Editor, CrunchYourDollars
Marcus Reed builds the sizing tools on CrunchYourDollars. He is a software engineer with a long-running PC hardware and power supply habit, which is where the watts, watt-hours and surge math on this site comes from. Product specs are pulled from manufacturer data sheets, electricity rates from the U.S. Energy Information Administration, and water chemistry rules from the Water Quality Association. He is not a licensed electrician or plumber: the tools show the math and the matching models so you can make the call, and anything involving your electrical panel should be checked by a licensed pro.
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