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  • Writer's pictureJulia Roy

How Much Does It Cost to Run AC Units?

When summer rolls around, you can expect your energy bills to spike. This is a bummer for many homeowners after a nice month or so of low energy costs, thanks to spring’s mild temperatures. You’ve probably wondered how much does it cost to run an AC, which is helpful to know so you can estimate your summertime utility costs and stick to your budget.

There is no one answer for how much does it cost to run an AC unit, as all homes are different and several variables will affect the cost. Learn what those are, how they affect your cooling costs, as well as averages so you can estimate your seasonal cooling costs.

Variables Affecting How Much It Costs to Run AC

There are a few factors that will affect how much it costs to run AC units – no two households are likely to have the same exact costs. Here are the variables and how they impact your AC operating costs:

  • Energy costs: The amount you pay per unit of energy consumed will affect how much your total AC costs are. Electric utility providers typically charge by the kilowatt/hour, or kWh. In the U.S., the average cost per kWh is 12 cents. You can find out exactly how much you are charged per kWh by contacting your utility provider, or checking your last utility statement for the cost. The U.S. Energy Information Administration has compiled a list of the average kWh costs by state.

  • AC energy efficiency: The SEER rating of your air conditioner will also affect how much it costs to run the AC. Units with higher SEER ratings are more energy efficient, meaning they produce more cooling per unit of energy consumed. With proper installation, a unit with a higher SEER will cost less to cool a home versus a unit with a lower SEER rating under the same conditions.

  • Thermostat settings: How you program or set your thermostat will greatly affect how much it costs to run the AC. Keeping the temperatures lower for longer will cost you more, while setting them higher for longer periods of time will keep costs down. Learn how to program and set your thermostat more efficiently to keep your cooling costs lower over the summer months.

  • Outdoor conditions: In the summertime, outdoor weather and temperatures can vary greatly. During periods of extreme heat and high humidity, your air conditioner works harder to keep your home cool. These conditions will affect how much it costs to run the AC, and you will likely notice higher utility bills when temps are very hot.

  • AC installation, maintenance, and ducts: If your AC system wasn’t installed properly, your unit will not deliver the efficiency level you expect. Also, if you do not have your cooling system professionally maintained each season or fail to change the furnace filter regularly, your system will consume more energy to provide cooling. Duct leaks in your duct system can result in up to 30 percent energy loss, forcing your air conditioner to work more to cool your home and driving up utility costs.

  • Size of home: As you may imagine, larger homes cost more to cool than smaller ones, because there is more space to cool. Limiting rooms to be cooled with zoning systems can reduce the cooling load and keep energy costs lower.

Formula for Determining AC Costs to Operate

To determine how much energy your air conditioner consumes and how much does it cost to run your AC, you can estimate it using energy regarding your unit and plugging it into a formula.

  • First, determine the amps drawn by the unit. This will depend on the unit’s size and SEER rating. For example, we will use a 16 SEER air conditioner. A 2-ton AC at this SEER rating is approximately 15 amps; 3-tons is 18 amps; 4-tons is 21 amps.

  • Next, calculate the wattage consumed. A typical whole-home air conditioner uses a 240-volt power outlet. Multiply the amps by 240 watts, which equals 4,320 watts.

  • To find the kWh, divide by 1,000. 4,320 watts / 1,000 = 4.32 kWh.

How Much Does It Cost to Run AC for an Hour?

Use your kWh unit cost to find out how much does it cost to run the AC for an hour. For example,’s headquarters is in Ohio, and the average residential kWh cost is 12.55. Our 3-ton air conditioner that uses 4.32 kWh multiplied by the kWh cost of 12.55 equals 54.216. This is $0.54216. This is the cost to run an air conditioner for an hour.

The formula is kWh x kWh unit cost = cost to operate an AC for an hour.

To determine how much it will cost you to run your air conditioner all summer, total the number of hours the unit will run over the season and multiply by the kWh cost.

How Much Does It Cost to Run AC All Day?

To find out how much does it cost to run AC all day, use the cost you found for the one-hour period, and multiply it by the amount of hours your AC runs during the day. This number varies between households, as many families set back their thermostats while gone for the day, while other homes may be occupied throughout the day.

This total varies greatly based on the temperatures you keep your home and for how long, as well as the outdoor temperature. This general total will give you a rough idea of how much it will cost to run the system throughout the day.

Let’s say your air conditioner runs for 8 hours out of the day total. $0.54216 x 8 hours = $4.33728

How Much Does It Cost to Run AC All Night?

To find out how much does it cost to run AC all night, determine how many hours your air conditioner will run overnight. For the purpose of example, let’s say your air conditioner runs 7 hours each night.

$0.54216 x 7 hours = $3.79512

Find AC Help through

For assistance with your air conditioning questions as well as installation, repair, and maintenance help, find a local cooling professional who can help you find specific solutions for your household. On’s Contractor Directory, enter your ZIP code to see a list of all HVAC contractors serving your area who can assist you.

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