How much does it cost to run a central air conditioner?
A central air conditioner drawing 3,500 watts, used 8 hours a day, uses about 28.00 kWh per day and costs about $5.43 per day, $165.44 per month, and $1,983.70 per year at the US average residential rate of 19.4¢/kWh. Enter your own wattage, hours, and state below for an exact figure.
Estimates only — based on typical wattages and average state rates, not your actual bill.
What drives the cost
Central AC is usually the single largest electricity expense in a home during summer. Draw depends on system size (measured in tons) and efficiency (SEER rating): an older 3-ton unit might pull 3,500 watts while a modern high-SEER system of the same capacity pulls closer to 2,000. Actual runtime matters more than nameplate wattage, since the compressor cycles rather than running flat out.
Cost at different daily usage
Same central air conditioner at 3,500 watts, run for different amounts of time, at 19.4¢/kWh.
| Usage | kWh/day | Per day | Per month | Per year |
|---|---|---|---|---|
| 4 h/day | 14.00 kWh | $2.72 | $82.72 | $991.85 |
| 8 h/day | 28.00 kWh | $5.43 | $165.44 | $1,983.70 |
| 12 h/day | 42.00 kWh | $8.15 | $248.15 | $2,975.55 |
| 16 h/day | 56.00 kWh | $10.87 | $330.87 | $3,967.40 |
Cost by model power draw
Not all models are equal. At 8 h/day, here is what the range costs.
| Model | Power | kWh/day | Per day | Per month |
|---|---|---|---|---|
| Low-draw model | 2,000 W | 16.00 kWh | $3.11 | $94.53 |
| Typical | 3,500 W | 28.00 kWh | $5.43 | $165.44 |
| High-draw model | 5,000 W | 40.00 kWh | $7.76 | $236.34 |
Cost by state
A central air conditioner at 3,500 W for 8 h/day, priced at each state's average residential rate.
| State | Rate | Per day | Per month | Per year |
|---|---|---|---|---|
| Alabama | 16.8¢ | $4.70 | $142.93 | $1,713.89 |
| Alaska | 28.2¢ | $7.90 | $240.61 | $2,885.11 |
| Arizona | 15.2¢ | $4.26 | $129.81 | $1,556.51 |
| Arkansas | 14.4¢ | $4.02 | $122.39 | $1,467.59 |
| California | 33.2¢ | $9.31 | $283.40 | $3,398.15 |
| Colorado | 16.2¢ | $4.52 | $137.73 | $1,651.55 |
| Connecticut | 27.4¢ | $7.66 | $233.28 | $2,797.21 |
| Delaware | 19.4¢ | $5.43 | $165.18 | $1,980.64 |
| District of Columbia | 25.4¢ | $7.11 | $216.49 | $2,595.88 |
| Florida | 15.2¢ | $4.25 | $129.30 | $1,550.37 |
| Georgia | 15.8¢ | $4.44 | $135.01 | $1,618.85 |
| Hawaii | 52.0¢ | $14.56 | $443.21 | $5,314.40 |
| Idaho | 12.3¢ | $3.46 | $105.26 | $1,262.17 |
| Illinois | 23.9¢ | $6.68 | $203.28 | $2,437.47 |
| Indiana | 18.1¢ | $5.08 | $154.70 | $1,854.93 |
| Iowa | 14.1¢ | $3.96 | $120.52 | $1,445.11 |
| Kansas | 15.1¢ | $4.24 | $128.96 | $1,546.29 |
| Kentucky | 15.0¢ | $4.19 | $127.68 | $1,530.96 |
| Louisiana | 14.2¢ | $3.96 | $120.60 | $1,446.13 |
| Maine | 28.6¢ | $8.02 | $244.02 | $2,925.99 |
| Maryland | 21.8¢ | $6.10 | $185.55 | $2,224.89 |
| Massachusetts | 28.8¢ | $8.07 | $245.64 | $2,945.40 |
| Michigan | 22.0¢ | $6.16 | $187.60 | $2,249.42 |
| Minnesota | 16.9¢ | $4.75 | $144.47 | $1,732.29 |
| Mississippi | 16.2¢ | $4.52 | $137.73 | $1,651.55 |
| Missouri | 13.7¢ | $3.83 | $116.60 | $1,398.10 |
| Montana | 14.7¢ | $4.11 | $125.04 | $1,499.27 |
| Nebraska | 13.6¢ | $3.81 | $115.83 | $1,388.90 |
| Nevada | 13.6¢ | $3.81 | $115.92 | $1,389.92 |
| New Hampshire | 27.3¢ | $7.65 | $232.94 | $2,793.13 |
| New Jersey | 23.3¢ | $6.52 | $198.33 | $2,378.19 |
| New Mexico | 14.1¢ | $3.95 | $120.35 | $1,443.06 |
| New York | 29.9¢ | $8.38 | $255.10 | $3,058.85 |
| North Carolina | 15.1¢ | $4.23 | $128.62 | $1,542.20 |
| North Dakota | 13.6¢ | $3.81 | $116.00 | $1,390.94 |
| Ohio | 19.5¢ | $5.47 | $166.37 | $1,994.94 |
| Oklahoma | 13.4¢ | $3.75 | $114.04 | $1,367.44 |
| Oregon | 16.3¢ | $4.56 | $138.67 | $1,662.79 |
| Pennsylvania | 21.6¢ | $6.03 | $183.67 | $2,202.41 |
| Rhode Island | 29.5¢ | $8.25 | $251.09 | $3,010.81 |
| South Carolina | 16.2¢ | $4.53 | $137.91 | $1,653.60 |
| South Dakota | 15.7¢ | $4.40 | $134.07 | $1,607.61 |
| Tennessee | 14.5¢ | $4.05 | $123.33 | $1,478.83 |
| Texas | 16.4¢ | $4.60 | $140.12 | $1,680.17 |
| Utah | 13.0¢ | $3.63 | $110.46 | $1,324.51 |
| Vermont | 24.9¢ | $6.97 | $212.14 | $2,543.76 |
| Virginia | 17.6¢ | $4.93 | $150.09 | $1,799.74 |
| Washington | 14.9¢ | $4.19 | $127.42 | $1,527.89 |
| West Virginia | 16.8¢ | $4.70 | $143.19 | $1,716.96 |
| Wisconsin | 19.7¢ | $5.53 | $168.25 | $2,017.43 |
| Wyoming | 14.8¢ | $4.14 | $126.14 | $1,512.56 |
How to cut the cost
- Raise the setpoint a few degrees — each degree typically trims several percent off cooling cost.
- Replace filters on schedule; a clogged filter makes the system run longer for the same result.
- Use ceiling fans to raise the comfortable setpoint — fans cost a fraction of what compressors do.
- Have the refrigerant charge and airflow checked if runtime has crept up year over year.
Compare with related appliances
Monthly cost at typical usage and 19.4¢/kWh.
Questions
Is it cheaper to leave the AC on all day or turn it off?
For most homes, setting the thermostat higher while you're out costs less than maintaining a cool temperature all day. The system works harder on return, but it runs far fewer total hours.
How much does central air cost per month?
It varies enormously with climate, house size, and setpoint. The table below shows what continuous-equivalent runtime costs at your state's rate; most households land well below the 8-hour figure in shoulder seasons and above it in peak summer.
How do you calculate what a central air conditioner costs to run?
Multiply its wattage by the hours it runs per day, divide by 1,000 to get kilowatt-hours, then multiply by your electricity rate. For a central air conditioner: 3,500 W × 8 h ÷ 1,000 = 28.00 kWh per day, which at 19.4¢/kWh is $5.43 per day.
How many watts does a central air conditioner use?
Typically 3,500 watts, with most models falling between 2,000 and 5,000 watts. The label on the appliance or its power supply gives the figure for your specific unit.