Home / Heating & Cooling / Window air conditioner
How many watts does a window air conditioner use? (900 W)
A window air conditioner uses about 900 W
Typical range 500–1,500 watts, plus ~1 W on standby.
Typical range 500–1,500 watts, plus ~1 W on standby.
Running cost calculator
Per hour—
Per day—
Per month—
Per year—
Energy/mo—
A window AC cools one room, so it draws far less than central air but still runs for long stretches in summer.
Window air conditioner power specs
| Typical running power | 900 W |
| Typical range | 500–1,500 W |
| Startup surge | 1,800 W |
| Standby draw | 1 W |
| Energy use | 5.40 kWh/day · 162.0 kWh/mo |
What affects the wattage
- Model size, age and energy rating.
- Settings and how hard it works (heat, speed, load).
- How many hours a day you run it.
Running cost at $0.17/kWh
| Electricity rate | Per day | Per month | Per year |
|---|---|---|---|
| $0.10/kWh | $0.54 | $16.20 | $197.10 |
| $0.15/kWh | $0.81 | $24.30 | $295.65 |
| $0.20/kWh | $1.08 | $32.40 | $394.20 |
| $0.25/kWh | $1.35 | $40.50 | $492.75 |
| $0.30/kWh | $1.62 | $48.60 | $591.30 |
| $0.40/kWh | $2.16 | $64.80 | $788.40 |
See the full breakdown of what it costs to run a window air conditioner, or what size power station runs a window air conditioner.
FAQ
How many watts does a window AC use?
Around 500-1500 watts depending on the cooling capacity (BTU rating).
What size generator runs a window AC?
Plan for the startup surge - many need 1500-2000 starting watts even if running watts are lower.
More in Heating & Cooling