How much electricity does an air conditioner use?

It takes 2,365 kilowatt-hours (kWh) of electricity per year to cool an average home in the U.S., according to an EnergySage analysis of a Department of Energy building database. That’s enough electricity to run four full-size refrigerators all year, or keep a Tesla Model 3 rolling for about 6,500 miles.

That number swings widely depending on your air conditioner type, your home, and your climate. For example, a large, poorly insulated home in Phoenix might use over 12,000 kWh on cooling alone, while an efficient apartment in San Francisco might use less than 400 kWh.

Below, we'll break down electricity use and monthly cost by AC type, answer the "is this normal" question everyone wants answered, and walk through three ways to estimate your own AC's usage.

Yes, air conditioning is typically the biggest driver of a summer electric bill, but "a lot" depends heavily on which kind of AC you're running.

Cooling makes up about 9% of the average home's electricity use over a full year, according to the Energy Information Administration (EIA). That number is deceptively low, though, because it's an annual average, but most of us only run our AC for three to five months of the year, tops. During the hottest months of summer, cooling can account for 30% or more of your bill.

Central air is the heaviest user by far because it's cooling your whole home at once. A single window unit or one zone of a ductless mini split uses a fraction of that because its only cooling one room. For context, a large window unit running eight hours a day will add about $40 to your monthly electric bill, while central air will add $100 or more on the same schedule.

So while a single window unit doesn't use a lot of electricity compared to central air, running three or four of them at once will creep the price up toward a central system.

A handful of factors affect your actual cooling costs:

• AC type. Central air, window units, portable ACs, and mini-splits all use electricity differently, even at the same BTU rating (more on that below.)

• Local climate. Warmer weather means more energy for cooling, and high humidity adds to the load. Look at the IECC map below to see where your home falls.

• Home size and layout. Unsurprisingly, bigger homes generally need more energy to cool. Finished basements need little cooling, and box-shaped homes cool more efficiently than sprawling ones.

• Weatherization. Better insulation and fewer air leaks means your AC doesn't have to work as hard to hit the same temperature.

• Existing ductwork. Leaky or undersized ducts drive up energy use in central systems. Ductless cooling sidesteps this problem entirely.

• Thermostat setting. Every degree you lower your thermostat adds about 3% to your cooling costs.

• Efficiency rating. A higher SEER (or SEER2) rating cuts energy use significantly, though humidity can complicate the math.

• Installation quality. A sloppy install can drive up energy costs and cause issues, no matter how efficient the equipment is on paper.

Here's how the major AC types compare, using typical running wattage and a common eight-hour daily cooling schedule.

*Assumes eight hours of active cooling per day and the national average residential electricity rate of 18.44 cents/kWh as of August 2026, according to EIA data. Your actual runtime and local rate will vary; see the climate-zone breakdown further down for central air specifics.

A few things worth knowing about that table:

Portable ACs use noticeably more electricity than window units of a similar size. That's because a single-hose portable pulls some of its own cooled air back outside through the exhaust hose, so it has to work harder to hit the same temperature. If you're choosing between the two for the same room, a window unit will almost always cost less to run.

Mini-splits punch above their weight on efficiency. Their inverter-driven compressors ramp output up and down to match the actual heat load instead of just switching on and off, which is why a single-zone mini-split can cool a room using less electricity than a similarly sized window unit or portable AC. We cover mini-splits versus window ACs in more detail if you're weighing the two.

Central air costs the most in absolute terms because it's cooling an entire house, not one room. But it's also handling a job that would otherwise require several room units running at once, so it's not necessarily the least efficient option per square foot.

The table above is a good starting point, but your actual number depends on your specific home. Here are three ways to narrow it down.

1. Check your old energy bills

This takes a bit of digging, but it's usually the most accurate method. Pull up your electric bills from last year's cooling season and try to isolate the cooling costs from the rest of your usage. An easy shortcut: find a bill from a month when you barely used your AC, and use that as your baseline. Everything above it during summer is roughly your cooling cost.

Track both the kWh and the dollar amount, since you'll want both numbers if you're estimating savings from an upgrade.

If you're comparing your current AC to a new one, you'll need:

• Your current equipment's efficiency. Look for a SEER or SEER2 rating on a sticker or badge on the unit. Most equipment still in service falls somewhere between SEER 10 and SEER 14.

• Your new equipment's efficiency. High-performance heat pumps, the kind that can also heat your home in cold weather, typically hit at least 16 SEER2, and sometimes as high as 20 SEER2.

Plug those numbers into an AC energy savings calculator for a solid estimate.

2. Compare to similar homes

Based on our analysis of the Department of Energy's ResStock database, here's how much a whole-house cooling system tends to use across climates, home sizes, and efficiency levels.

Whole-house cooling energy use estimates, 15 SEER (14.3 SEER2), kWh per year

Notice how wide the spread is even within a single climate zone. A bigger or less-efficient home can use five times as much electricity for cooling as a smaller, more-efficient one nearby. In milder climates, the spread gets even wider, since some homes there use no cooling at all.

A couple of notes on the data: about 23% of homes in colder climates only cool part of the house, and we normalized those to whole-house cooling here for easy comparison. We also excluded the roughly 10% of U.S. homes, mostly in marine climates (3C, 4C) and very cold ones (6, 7, 8), that don't use cooling at all.

That 15 SEER baseline is the minimum efficiency you'll find on the market today. Here's how the numbers shift with older or newer equipment.

How SEER rating affects annual cooling energy use, median by climate zone (kWh/year)

3. Calculate it from the wattage

For basic, single-speed central air conditioners, you can estimate annual energy use directly from the wattage and the SEER rating. This method gets less reliable for inverter-driven ACs and heat pumps, since their wattage shifts constantly, but it's a useful gut check for older equipment.

First, find the running wattage during a cooling cycle:

Cooling wattage = Btu ÷ SEER

(If you're working with a SEER2 rating, multiply by 1.05 to get the rough equivalent on the standard SEER scale.)

Basic, single-stage air conditioner power draw

From there, multiply the wattage by your estimated daily runtime to get daily energy use:

Daily energy use (kWh) = Cooling wattage × hours in use ÷ 1,000

Multiply that out to monthly or seasonal totals. This method is only as good as your runtime estimate, and almost nobody tracks that precisely, so treat it as a rough cross-check rather than a final answer.

Multiply your estimated energy use by your electricity price per kWh, and you've got your cost. The table below applies the national average residential rate, 18.44 cents/kWh as of August 2026 per EIA data, to the median cooling energy use from each climate zone above.

Estimated annual central AC cost, median home cooling energy use, 15 SEER

*Based on the national average electricity rate. Local rates vary widely, sometimes by a factor of two or more, so check your own utility bill for a more precise number.

Cooling is one of the biggest, most predictable drains on a summer electric bill, and it's also one of the easiest to offset. A solar system sized to your home can generate enough electricity to cover your AC's usage—whatever type you run—along with the rest of your household's needs.

That's especially true if your air conditioner is the reason your bill spikes every summer. Solar panels produce the most power on the same hot, sunny days your AC works hardest, so the timing lines up perfectly.

The EnergySage Marketplace makes it easy to get and compare multiple quotes from vetted local solar installers, so you can see what going solar would actually cost and save for your home.