An air conditioner draws about 900 watts, or 0.90 kWh per hour. Enter your hours and electricity rate below for the exact cost per day, month and year.
Wattage is pre-filled with a typical value for an air conditioner; change any field for your own device, usage and rate. Cost uses your rate × kWh — a US-average placeholder rate of $0.17/kWh is shown; enter your own from your bill for an accurate figure.
An air conditioner draws about 900 watts while running. Energy is billed in kilowatt-hours (kWh), and one kWh is 1000 watts for one hour — so an air conditioner uses 900 ÷ 1000 = 0.90 kWh for every hour it is on. Multiply that by the hours you use it and by your rate per kWh to get the cost. The calculator above does it live; change the wattage if your model differs. Kept up every day of the year at 8 hours a day, that is about 2,628 kWh — roughly $446.76 at the $0.17/kWh placeholder rate used here, though most homes only run an air conditioner for part of the year, so scale that to the months you actually use it.
That is a window unit, and cooling capacity sets the draw. Dividing rated BTU/h by the CEER value on ENERGY STAR's certified room-air-conditioner list gives a median of roughly 400 W at 5,000–6,000 BTU, 530 W at 8,000 BTU, 670 W at 10,000 BTU and 800 W at 12,000 BTU — so the 900 W default here matches a large 12,000–14,000 BTU unit. A central air-conditioning system typically draws about 3500 W.
Wattage moves with size, age and model, so treat 900 W as a mid-range starting point rather than a fixed number — the rating plate on your own appliance, or its ENERGY STAR listing, gives the figure to type in. The rate matters just as much: the US Energy Information Administration publishes current average residential prices by state, and the figure on your own bill is better still. This LK Forge calculator recomputes every result as you type.
Two levers change the bill: hours of use and your rate per kWh. Running high-wattage devices less, or shifting them to off-peak hours on a time-of-use plan, has the biggest effect. For a whole-home estimate or to compare devices, use the full electricity bill & appliance calculator.