Central Air Conditioner cost calculator
Find it on the label.
Use the price from your bill if you know it.
Cost to run this device
Cost = watts divided by 1,000, times hours, times your price per kWh. It covers energy only, not the cost of buying the device.
Typical draw
3,500 W
Range 2,000 to 5,000 W
Hours a day
8
Assumed day of use
Energy a month
851 kWh
28.0 kWh a day
Cost a month
$147
At 17.23 cents per kWh
What a central air conditioner costs to run
| Period | Energy | Cost |
|---|---|---|
| One hour of running | 3.50 kWh | $0.60 |
| One day (8 hours) | 28.00 kWh | $4.83 |
| One month (30.4 days) | 851 kWh | $147 |
| One year (4 months of use) | 3,405 kWh | $587 |
Source: Planning watts of 3,500 and 8 hours a day, hours of compressor running time on a hot day. Price: 17.23 cents per kWh, the 2025 US residential average from EIA Form EIA-861.
The monthly cost is 97% of the $150.68 average US electric bill. Because it runs only about 4 months a year, the yearly cost is 4 times the monthly figure, not twelve.
Three real-life cases
One figure cannot fit every home. These three cases show how much the answer moves with the equipment and the hours.
| Case | Watts | Hours a day | kWh a month | Cost a month |
|---|---|---|---|---|
| Small home, efficient system | 2,000 | 6 | 365 | $63 |
| Typical house | 3,500 | 8 | 851 | $147 |
| Large house, older system | 5,000 | 11 | 1,672 | $288 |
The lowest case costs $63 a month and the highest $288. Use the calculator above to match your own.
What it costs in other states
The same central air conditioner costs different amounts depending on the state, because the price per kWh differs. Here are the three cheapest states, the US average and the three costliest, for the same 851 kWh a month.
| Place | Cents per kWh | Cost a month |
|---|---|---|
| North Dakota | 11.82 | $101 |
| Idaho | 11.83 | $101 |
| Nebraska | 12.05 | $103 |
| United States average | 17.23 | $147 |
| Hawaii | 40.40 | $344 |
| California | 31.35 | $267 |
| Massachusetts | 30.41 | $259 |
Source: U.S. Energy Information Administration, Form EIA-861 (final 2025 data). Price is residential revenue divided by sales and includes fixed charges.
See electricity rates in every state to find your own.
How a central air conditioner uses electricity
A central system moves cooled air through ducts, and the outdoor compressor and the indoor blower both draw power. The nameplate shows the maximum current for the breaker, and the real draw is usually lower once the system is up to speed.
System size, efficiency rating, duct leakage and the home’s insulation all affect the cost. A newer, higher-efficiency system uses noticeably less power than an old one for the same cooling.
For scale, the EIA Residential Energy Consumption Survey found the average US home used about 171 kWh a month on air conditioning in 2020, and the average detached house about 209 kWh. These averages include homes with no such equipment, so a home that has it uses more.
The range for this kind of appliance runs from about 2,000 to 5,000 watts. At 8 hours a day that is $84 to $210 a month, which is why checking the label on yours is worth the minute.
Ways to cut the cost of a central air conditioner
- Have the system serviced before summer and replace the filter on schedule.
- Seal and insulate ducts that run through hot attics.
- A smart thermostat with a schedule trims hours without a comfort loss.
Next step: Heat pump versus furnace calculator. For general ideas, read how to lower your electric bill.
Other appliances in the cooling group: Air Conditioner, Window Air Conditioner, Portable Air Conditioner, Ceiling Fan, Mini-Split Heat Pump, Whole-House Fan.
How we got these numbers
The cost is watts divided by 1,000, times hours, times your price per kWh. The 3,500 watts is a planning figure for this kind of appliance, set from typical product ratings, and the 8 hours is an assumed day of use. Neither is copied from a federal table. Federal guidance describes the method and warns that real wattage varies, so we publish our own typical ranges and label them as such. Prices come from EIA Form EIA-861 for 2025.
The calculation is the standard one used in the U.S. Department of Energy's consumer guidance on estimating appliance energy use. Wattage varies by product age and features, so the label on your own appliance beats any average. Read more in our methodology.
Central Air Conditioner cost questions
How much does it cost to run central air for a month?
It depends on hours of compressor running time and your price per kWh. The tables on this page price a mild summer, a typical one and a hot one at the US average price, and the calculator lets you use your own.
Does a bigger air conditioner cool faster and cost less?
No. An oversized system cools quickly, shuts off and restarts often. That wears the equipment and leaves the air damp, because the system never runs long enough to pull moisture out.
How much does a central air conditioner cost to run per hour?
At 3,500 watts and the 2025 US average price of 17.23 cents per kWh, about $0.60 an hour. Use your own price to get your own figure.
How many kWh does a central air conditioner use in a month?
About 851 kWh for 8 hours of use a day over 30.4 days at 3,500 watts. A different wattage or schedule changes the total in proportion.