How many watts does a window AC use?
A window AC uses 500–1,500 W (about 900 W on average). Running 8 hours/day, that is about 7.20 kWh a day and 216.0 kWh a month — roughly $39.55 a month at the U.S. average rate of 18.31 ¢/kWh.
This is the window AC electricity usage reference: watts, amps on a 120 V circuit, the kWh math, and links to what that usage costs in each state.
Watts, amps, and kWh for a window AC
| Measure | Value |
|---|---|
| Rated wattage range | 500–1,500 W |
| Average draw used in our math | 900 W |
| Amps at 120 V | 4.2–13 A (7.5 A at the average draw) |
| kWh per hour | 0.90 kWh |
| kWh per day at 8 hours/day | 7.20 kWh |
| kWh per month | 216.0 kWh |
| Cost per month at the U.S. average (18.31 ¢/kWh) | $39.55 |
The math is kWh = watts × hours ÷ 1000 and amps = watts ÷ volts. A standard 120 V household circuit on a 15 A breaker carries about 1,800 W. For the dollars in your state, open cost to run a window AC in Texas and switch states from there.
Window AC electricity usage profile
| Metric | Value |
|---|---|
| kWh per hour | 0.90 kWh |
| kWh per day (typical) | 7.20 kWh |
| kWh per month (typical) | 216.0 kWh |
| kWh per year (typical) | 2628.0 kWh |
| Low runtime scenario | 4 hours/day |
| High runtime scenario | 12 hours/day |
Connect usage to cost tools
Related appliance usage pages
Source & Method
Source: U.S. Energy Information Administration (EIA) Retail Sales of Electricity. Last dataset period: July 2026. Usage calculations use fixed appliance wattage and runtime assumptions so results stay comparable across pages.
Frequently asked questions
How many watts does a window AC use?
A window AC uses 500–1,500 W (about 900 W on average). Our usage and cost math uses 900 watts running 8 hours/day.
How many amps does a window AC draw?
On a 120 V circuit, 500–1,500 W works out to about 4.2–13 A; at the 900 W we use in the math that is 7.5 A.
How much electricity does a window AC use per month?
About 216.0 kWh a month at 8 hours/day. Lighter use (4 hours/day) comes to roughly 108.0 kWh and heavier use (12 hours/day) roughly 324.0 kWh.
How much does it cost to run a window AC?
About $39.55 a month at the U.S. average rate of 18.31 ¢/kWh — from roughly $27.48 in Louisiana to $103.68 in Hawaii at the same usage. The state cost-to-run pages price it at every state's rate.