Central air conditioner: electricity cost calculator
Quick answer: a typical central air conditioner costs about $157/month while in use at the U.S. average electricity price (18.44¢/kWh) across a 5-month season (about $786/year). Your number depends on wattage, runtime and your state — calculate it below.
A typical 3-ton central AC draws 3,000–4,000 W while the compressor runs. On hot days the compressor may run 8–12 hours in total; the preset uses 8 hours of actual runtime during a 5-month cooling season, not year-round.
28.00 kWh/day used · 852 kWh/month in use · 4261 kWh/year at 18.44¢ per kWh (5 months of use per year)
Typical running watts by system size (SEER2 ≈ 14–15)
Monthly cost assumes the preset 8 h/day at the U.S. average price of 18.44¢/kWh — enter your size's wattage in the calculator above for exact numbers.
| Size | Running watts | Per month in use |
|---|---|---|
| 1.5 tons (18,000 BTU) | ~1,800 W | $81 |
| 2 tons (24,000 BTU) | ~2,300 W | $103 |
| 2.5 tons (30,000 BTU) | ~2,900 W | $130 |
| 3 tons (36,000 BTU) | ~3,500 W | $157 |
| 4 tons (48,000 BTU) | ~4,700 W | $211 |
| 5 tons (60,000 BTU) | ~5,800 W | $260 |
Low, typical and heavy use
Monthly cost while in use, at the U.S. average price of 18.44¢/kWh.
| Scenario | Watts | Hours/day | Per month |
|---|---|---|---|
| Light use | 2,800 W | 4.8 h | $75.43 |
| Typical | 3,500 W | 8.0 h | $157.15 |
| Heavy use | 5,000 W | 12.0 h | $336.76 |
Common questions
Why does my AC cost more than this estimate?
The two usual reasons are longer compressor runtime (poor insulation, extreme heat, thermostat set very low) and an older unit with a low SEER rating drawing more watts for the same cooling.
Does turning the thermostat up 2–3 degrees really help?
Yes. Each degree of setpoint typically changes cooling energy by roughly 3–5%, because the compressor runs fewer minutes each hour.
Window units vs central AC — which is cheaper?
Cooling one or two rooms with window units is usually cheaper than running central AC for the whole house. Cooling the same whole house, central systems are typically more efficient per BTU.
Cost in every state
Monthly cost of a typical central air conditioner (3,500 W, 8h/day) at each state's average residential price, May 2026.
| State | Avg price | Per month |
|---|---|---|
| Alabama | 16.77¢ | $142.92 |
| Alaska | 28.23¢ | $240.59 |
| Arizona | 15.23¢ | $129.80 |
| Arkansas | 14.36¢ | $122.38 |
| California | 33.25¢ | $283.37 |
| Colorado | 16.16¢ | $137.72 |
| Connecticut | 27.37¢ | $233.26 |
| Delaware | 19.38¢ | $165.17 |
| District of Columbia | 25.40¢ | $216.47 |
| Florida | 15.17¢ | $129.29 |
| Georgia | 15.84¢ | $135.00 |
| Hawaii | 52.00¢ | $443.17 |
| Idaho | 12.35¢ | $105.25 |
| Illinois | 23.85¢ | $203.26 |
| Indiana | 18.15¢ | $154.68 |
| Iowa | 14.14¢ | $120.51 |
| Kansas | 15.13¢ | $128.95 |
| Kentucky | 14.98¢ | $127.67 |
| Louisiana | 14.15¢ | $120.59 |
| Maine | 28.63¢ | $244.00 |
| Maryland | 21.77¢ | $185.53 |
| Massachusetts | 28.82¢ | $245.62 |
| Michigan | 22.01¢ | $187.58 |
| Minnesota | 16.95¢ | $144.46 |
| Mississippi | 16.16¢ | $137.72 |
| Missouri | 13.68¢ | $116.59 |
| Montana | 14.67¢ | $125.03 |
| Nebraska | 13.59¢ | $115.82 |
| Nevada | 13.60¢ | $115.91 |
| New Hampshire | 27.33¢ | $232.92 |
| New Jersey | 23.27¢ | $198.32 |
| New Mexico | 14.12¢ | $120.34 |
| New York | 29.93¢ | $255.08 |
| North Carolina | 15.09¢ | $128.60 |
| North Dakota | 13.61¢ | $115.99 |
| Ohio | 19.52¢ | $166.36 |
| Oklahoma | 13.38¢ | $114.03 |
| Oregon | 16.27¢ | $138.66 |
| Pennsylvania | 21.55¢ | $183.66 |
| Rhode Island | 29.46¢ | $251.07 |
| South Carolina | 16.18¢ | $137.89 |
| South Dakota | 15.73¢ | $134.06 |
| Tennessee | 14.47¢ | $123.32 |
| Texas | 16.44¢ | $140.11 |
| Utah | 12.96¢ | $110.45 |
| Vermont | 24.89¢ | $212.13 |
| Virginia | 17.61¢ | $150.08 |
| Washington | 14.95¢ | $127.41 |
| West Virginia | 16.80¢ | $143.18 |
| Wisconsin | 19.74¢ | $168.23 |
| Wyoming | 14.80¢ | $126.13 |
Related calculators
Window air conditioner Cheap to buy; the running cost depends on runtime.
~900 W · 8h/day →
Portable air conditioner Convenient, but the least efficient way to cool a room.
~1,100 W · 8h/day →
Ductless mini-split Inverter compressors sip power once the room is at temperature.
~800 W · 8h/day →
Central heat pump Heats and cools — usually the cheapest electric heat available.
~3,000 W · 6h/day →
Space heater 1,500 watts adds up faster than most people expect.
~1,500 W · 6h/day →
Electric baseboard heater Simple, silent, and one of the priciest ways to heat.
~1,500 W · 8h/day →
Methodology & sources
Cost = watts ÷ 1,000 × hours × price per kWh. Electricity prices are average residential prices by state from the EIA Electric Power Monthly, Table 5.6.A (May 2026). EIA averages include delivery charges and taxes but are not any specific utility tariff — for an exact figure, use the rate from your own bill. Wattage presets reflect common product ranges; check your appliance's nameplate or a plug-in power meter for its true draw.
Last verified: July 30, 2026. Prices refresh automatically each month when EIA publishes new data.