# How to Calculate Cost of Running an 8000 BTU Window AC

In most American states, the kilowatt-hour cost of electricity ranges from about 6.35 to 13.17 cents and is substantially more in California and the Northeastern coastal states, according to estimates from All Systems Mechanical. While it's easy to not worry about a few cents at a time, those pennies add up over the hours, days and months you run your air conditioner.

Among other variables, your window unit's British Thermal Unit-based cooling power affects how much juice it uses, which in turn affects how much it costs to run. BTUs represent the amount of energy required to run the AC; one BTU is the amount of energy required to cool one pound of water by 1 degree Fahrenheit. Luckily, you won't have to break out a water bucket or a thermometer to figure out your own home's cooling cost; you'll just need to know its basic specs.

#### TL;DR (Too Long; Didn't Read)

In order to calculate the operating cost of your window AC unit, you will need to know the wattage uses by your unit and the total cost per kilowatt hour charged by your utility company.

## Understanding The Formula

To figure out how much it costs to operate your window-unit AC, you'll first need to know how many amps it draws. This info should be readily available via the unit's physical or online spec sheet. For an 8,000-BTU AC, this figure often hovers around 6.0 amps.

Once you have the amps, multiply that figure by the voltage of your AC (also available on the spec sheet) to figure out the wattage it uses. For a window unit, the voltage is usually 110 volts. For a 6-amp AC at 110 volts, your formula looks like this: 6 amps x 110 volts = 660 watts. Now, divide that sum by 1,000 to get the kilowatt hours for your air conditioner. In this case, the kilowatt hours equal 0.66.

Finally, it's time to break out your last electric bill to find out how much your utility company charges per kilowatt hour. Multiply the cost in cents by the kilowatt-hour sum (0.66, in the example) to estimate how much your window unit costs per hour to run.

## Evaluating Cost Estimates

If you'd rather not do the math yourself, Silicon Valley Power of Santa Clarita saves you some work and chimes in with the estimated costs of running an 8,000-BTU window unit AC. At 120 volts, the AC costs roughly \$0.08 per hour. If your AC runs for eight hours a day during seven months of the year, that's about \$134.40 annually.