How Much Does It Cost to Run an Air Conditioner (Window Unit)? (2026)
Window and portable air conditioners range from small 5,000 BTU units around 500 watts to 15,000 BTU units near 1,500 watts. Cost scales with outdoor temperature, insulation, and how low you set the thermostat.
A typical air conditioner (window unit) (1,000 W) costs $0.18 per hour, or about $44.02 per month at 8 hours a day in the US. Average running cost
| Wattage | Per hour | Per day | Per month | Per year |
|---|---|---|---|---|
| Low 500 W | $0.092 | $0.73 | $22.01 | $88.03 |
| Typical 1,000 W | $0.18 | $1.47 | $44.02 | $176.06 |
| High 1,500 W | $0.28 | $2.20 | $66.02 | $264.10 |
Formula: watts ÷ 1000 × hours × price per kWh. Typical use is 8 h/day for about 120 days a year (the cooling season) ≈ 960 kWh per year.
One hour of an air conditioner (window unit) (1.0 kWh) is the same electricity as
- 5.6km in an electric car
- 10hours of TV
- 22hours of a laptop
- 111hours of an LED bulb
Around the world per year at typical use, local prices
How to lower the cost of running an air conditioner (window unit)
- Every degree you raise the thermostat saves roughly 3 to 5 percent of cooling cost.
- Clean or replace the filter monthly in summer.
- Seal the gaps around a window unit with foam. Warm air leaking in is the biggest hidden cost.
- Use a fan alongside the AC. Moving air feels several degrees cooler at almost no cost.
In standby it draws about 2 W, which adds roughly 18 kWh ($3.21) per year if it is never unplugged.
Is an efficient air conditioner worth it?
Window unit from before 2010, EER around 8: about 750 kWh a year. ENERGY STAR window unit, CEER 12 or more: about 500 kWh. The difference is worth $45.85 a year in the US.
- Replacing one that still works pays back in 10.9 years.
- When yours needs replacing anyway, the extra cost of the efficient model pays back in 2.6 years.
Usage assumed: 750 hours of cooling a year, the official US test assumption. Typical prices: $500.00 for the efficient model, $120.00 more than a basic one. Work it out with your own prices
Frequently asked questions
How much does it cost to run an AC all day?
A 1,000 watt unit running 8 hours uses 8 kWh, so multiply by your local rate. Use the table above with your region selected.
Is a portable AC more expensive to run than a window unit?
Usually yes. Portable units are less efficient because they pull conditioned room air out through the exhaust hose.
What does EER mean?
Energy Efficiency Ratio: BTU of cooling per watt. Higher is cheaper to run.
Compare with
Cost by region
- United States (average)
- Canada (average)
- United Kingdom
- Germany
- France
- Australia
- India
US states
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- District of Columbia
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Canadian provinces
Related appliances
- Electric Blanket100 W typical
- Heat Pump (Ducted or Mini-Split)2,000 W typical
- Baseboard Heater1,500 W typical
- Portable Fan (Box or Pedestal)50 W typical
Use the generic electricity cost calculator · Which uses more? Take the quiz