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

A window air conditioner costs about 7.6¢ per hour, 61¢ a day, $18.49 a month and $74 a year at typical use (8 hours a day for 4 months a year) and the U.S. average rate of 17.99¢/kWh. Watts are for typical CEER 10-12 units. Inverter models such as the Midea U-shaped run at reduced speed most of the time and use 25-35% less.

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Cost by setting

Setting	Watts	Per hour	Per day	Per month	Per year
5,000 BTU	450	4.9¢	39¢	$11.92	$48
8,000 BTU	700	7.6¢	61¢	$18.49	$74
12,000 BTU	1,050	11¢	91¢	$27.69	$111
18,000 BTU	1,600	17¢	$1.38	$42.14	$169

At 8 hours a day for 4 months a year and 17.99¢/kWh.

Cost by hours of use

Hours per day	kWh/day	Per day	Per month	Per year (all year)
1 hour	0.44	8.0¢	$2.43	$29
2 hours	0.86	16¢	$4.72	$57
4 hours	1.70	31¢	$9.31	$112
8 hours	3.38	61¢	$18.49	$222
12 hours	5.05	91¢	$27.66	$332
24 hours	10.08	$1.81	$55.20	$662

Cost to run a window air conditioner in every state

The same window air conditioner costs $51 a year in North Dakota and $179 in Hawaii, at each state's average residential rate (12 months ending July 2026).

State	Rate	Per hour	Per month	Per year
North Dakota	12.32¢	5.2¢	$12.66	$51
Idaho	12.65¢	5.3¢	$13.00	$52
Nebraska	12.86¢	5.4¢	$13.21	$53
Louisiana	12.99¢	5.5¢	$13.35	$53
Utah	13.32¢	5.6¢	$13.69	$55
Nevada	13.36¢	5.6¢	$13.73	$55
Arkansas	13.43¢	5.6¢	$13.80	$55
Tennessee	13.56¢	5.7¢	$13.93	$56
Oklahoma	13.70¢	5.8¢	$14.08	$56
Montana	13.84¢	5.8¢	$14.22	$57
Kentucky	13.92¢	5.8¢	$14.30	$57
Missouri	13.95¢	5.9¢	$14.33	$57
Wyoming	14.01¢	5.9¢	$14.40	$58
Washington	14.12¢	5.9¢	$14.51	$58
Iowa	14.13¢	5.9¢	$14.52	$58
South Dakota	14.20¢	6.0¢	$14.59	$58
Mississippi	14.77¢	6.2¢	$15.18	$61
North Carolina	14.77¢	6.2¢	$15.18	$61
Kansas	15.09¢	6.3¢	$15.51	$62
Georgia	15.12¢	6.4¢	$15.54	$62
New Mexico	15.32¢	6.4¢	$15.74	$63
Florida	15.39¢	6.5¢	$15.81	$63
Arizona	15.40¢	6.5¢	$15.82	$63
West Virginia	15.48¢	6.5¢	$15.91	$64
Oregon	15.50¢	6.5¢	$15.93	$64
South Carolina	15.64¢	6.6¢	$16.07	$64
Texas	15.96¢	6.7¢	$16.40	$66
Minnesota	16.22¢	6.8¢	$16.67	$67
Alabama	16.44¢	6.9¢	$16.89	$68
Virginia	16.48¢	6.9¢	$16.93	$68
Colorado	16.58¢	7.0¢	$17.04	$68
Indiana	16.94¢	7.1¢	$17.41	$70
Delaware	17.79¢	7.5¢	$18.28	$73
Ohio	18.25¢	7.7¢	$18.75	$75
Wisconsin	18.74¢	7.9¢	$19.26	$77
Illinois	18.79¢	7.9¢	$19.31	$77
Pennsylvania	20.70¢	8.7¢	$21.27	$85
Maryland	21.03¢	8.8¢	$21.61	$86
Michigan	21.05¢	8.8¢	$21.63	$87
New Jersey	23.78¢	10.0¢	$24.44	$98
Vermont	23.80¢	10.0¢	$24.46	$98
District of Columbia	24.20¢	10¢	$24.87	$99
New Hampshire	26.67¢	11¢	$27.41	$110
Alaska	26.85¢	11¢	$27.59	$110
Connecticut	27.99¢	12¢	$28.76	$115
New York	28.39¢	12¢	$29.17	$117
Rhode Island	29.27¢	12¢	$30.08	$120
Maine	29.31¢	12¢	$30.12	$120
Massachusetts	30.43¢	13¢	$31.27	$125
California	32.99¢	14¢	$33.90	$136
Hawaii	43.51¢	18¢	$44.71	$179

Most efficient window air conditioner models

The lowest-energy ENERGY STAR certified models in the most common size (8,500–11,500 BTU/h), out of 548 certified models. In this class, the best model costs $69 a year to run. The least efficient costs $115. Same size, $46 a year apart.

Brand	Model	Cooling	kWh/yr	Cost/yr	Shop
Kühl	KCVS08B10B Most Efficient	8,700	384	$69	Amazon
Midea	MAH09B1AGR +6 variants Most Efficient	9,500	405	$73	Amazon
Friedrich	KCVS08B10A Most Efficient	8,700	408	$73	Amazon
Gradient	CCHP11 Most Efficient	9,300	415	$75	Amazon
LG	LW8024IVSM	8,500	425	$76	Amazon
GREE	GJH09BW-A6DRNL1B Most Efficient	9,300	433	$78	Amazon
GREE	GJH09BW-A6DRNL1A Most Efficient	9,300	462	$83	Amazon
Kinghome	KHWA09IN Most Efficient	9,300	462	$83	Amazon
BLACK+DECKER	BDM10C Most Efficient	10,000	469	$84	Amazon
DuraSTAR	DRWAC101XVB1 Most Efficient	10,000	469	$84	Amazon

Yearly cost from the official annual energy use and 17.99¢/kWh. Look up any model in the calculator with “Look up my exact model”. Source: ENERGY STAR, updated 2026-10-21. Amazon links search for the exact model; as an Amazon Associate we earn from qualifying purchases.

How to cut the cost

Set it to 76-78°F or use Eco mode so the compressor cycles instead of running constantly.
Clean the front filter every 2 weeks during summer; a clogged filter can raise energy use 5-15%.
Seal gaps around the unit with foam insulation strips and the side panels; leaks let hot air in.
Shade the outside of the unit if it faces south or west; a cooler condenser runs more efficiently.
Size it to the room: about 20 BTU per square foot. Oversized units short-cycle and leave the room clammy.

Cheaper ways to get the job done

Inverter window air conditioner

Variable-speed compressors use roughly 25-35% less energy than fixed-speed units.

See options on Amazon

Window AC insulation kit

Seals gaps that leak cooled air outside.

See options on Amazon

We may earn a commission from qualifying purchases. It never changes the numbers we show. Disclosure.

Compare with similar appliances

Appliance	Watts	Typical use	Per month	Per year
Window air conditioner	700	8 hours a day for 4 months a year	$18.49	$74
Portable air conditioner	1,100	8 hours a day for 4 months a year	$33.82	$135
Through-the-wall air conditioner	950	8 hours a day for 4 months a year	$25.06	$100
Mini split air conditioner	900	10 hours a day for 4 months a year	$27.49	$110
Box fan	75	8 hours a day for 5 months a year	$3.29	$16
Ceiling fan	40	8 hours a day	$1.84	$22
Evaporative cooler	150	8 hours a day for 5 months a year	$6.57	$33

Compare these side by side at your rate →

Head-to-head comparisons

Frequently asked questions

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

A window air conditioner drawing 700 watts uses 0.42 kWh per hour while running (60% duty cycle). At the U.S. average of 17.99¢/kWh that's 7.6¢ per hour. In North Dakota (12.32¢) it's 5.2¢. In Hawaii (43.51¢) it's 18¢.

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

At typical use (8 hours a day for 4 months a year), a window air conditioner costs about $18.49 a month while in use and $74 a year over the 4 months it's typically used, at the U.S. average rate. Enter your ZIP in the calculator above for your utility's rate.

How many watts does a window air conditioner use?

Most window air conditioners use 400 to 1,800 watts, depending on the setting (5,000 btu 450 W, 8,000 btu 700 W, 12,000 btu 1,050 W, 18,000 btu 1,600 W). Plugged in but off, it still draws about 1 W of standby power. Starting surge can reach 2,000 W. Check the label on the back or bottom for your model's exact rating.

How many kWh does a window air conditioner use?

About 3.38 kWh a day and 411 kWh a year at typical use (8 hours a day for 4 months a year).

Does a window air conditioner use a lot of electricity?

It's a moderate load: 411 kWh a year is about 4% of the average U.S. home's yearly use.

Is it cheaper to run a window air conditioner or a portable air conditioner?

At typical use, a window air conditioner costs about $74 a year versus $135 for a portable air conditioner. So the window air conditioner is cheaper by about $61 a year. Use the comparison table above to compare them at your own settings.

How can I lower the cost of running a window air conditioner?

Set it to 76-78°F or use Eco mode so the compressor cycles instead of running constantly.
Clean the front filter every 2 weeks during summer; a clogged filter can raise energy use 5-15%.
Seal gaps around the unit with foam insulation strips and the side panels; leaks let hot air in.

Rates updated 2026-10-21: EIA data through July 2026. Typical wattage and usage reviewed against DOE, ENERGY STAR and manufacturer specs. Methodology.