Window AC Electricity Cost Calculator
A window air conditioner is a far smaller electricity user than central AC, but for people cooling one or two rooms it's the main summer cost. A typical unit draws around 900 watts while running and cycles on and off to hold the room temperature. This calculator applies that duty cycle and shows what your window AC costs to run per hour, day, and month at your electricity rate.
watts × hours × duty ÷ 1000
at your state rate
this appliance
Results update live as you type. For planning and field-check estimates — always verify against applicable standards and equipment ratings.
Window AC costs: smaller unit, comparable math
A 5,000 BTU window unit draws about 450–500 W; a 10,000 BTU unit about 900–1,000 W; a 14,000 BTU unit about 1,200–1,400 W. Like all compressor-driven devices, window ACs cycle on and off — a 50% duty cycle is typical in moderate weather, meaning the compressor runs about half the time while the fan runs continuously.
Running three window units (900 W each at 50% duty) for 10 hours daily costs about $14/month at the U.S. average rate — considerably less than central AC, but it adds up when you're cooling multiple rooms. Energy Efficiency Ratio (EER) varies meaningfully across models: a 12 EER unit uses 30% less electricity than a 9 EER unit of the same BTU capacity. When buying, a higher EER rating pays back quickly in warm climates.
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