Informational Guide

How Much Does it Cost to Run an AC?

Considering buying an AC? Before you do, learn how much it costs to run any air conditioner with our guide. We break down different types used in the home.

by Josh M

People living in warmer climates know what a blessing an air conditioner is. We cannot imagine surviving the sweltering summer without an air-conditioned room to seek refuge in, which is why three-quarters of all US households use air conditioners.

However, extended AC usage leads to high electricity bills.

Therefore, before installing one, it is essential to know an AC’s running costs to adjust your budget accordingly. These costs are affected by several factors that can be monitored to prevent your electricity bills from soaring.

Follow this guide to learn how much it costs to run an air conditioner at home and the different factors that affect these costs.

seer rating chart

While it is true that various factors impact the costs to run an AC unit, these charges will also depend on the type of AC unit in use. Let’s explore this in detail:

Home Or Room Size

It is costlier to cool larger homes as opposed to smaller ones because of the difference in space. However, if you limit rooms with zoning systems to cool them down, you can significantly reduce the load on the AC unit, and in turn, your overall electricity bill will be lowered.


Your air conditioner’s SEER rating also influence the cost. The higher the SEER rating of a unit, the more energy-efficient it is, which will produce more cooling per every unit of energy consumed.

The cost of cooling a home will be less if a unit is installed correctly and has a higher SEER than one with a lower SEER rating in the same conditions.

Local Energy Cost

The amount charged per energy unit you consume significantly impacts your total AC costs. Electricity providers generally charge for ACs by kWh, and in the US, its average price is $12.

Depending on where you live, you can figure out how much your utility provider charges you by contacting them or looking for your latest utility statement.

Temperature Settings

Your usual temperature settings will also have a considerable impact on the cost to run an ac unit. If you have the AC set at a low temperature and run it for an extended period, the resultant bill would be high. Whereas, if you use a higher temperature setting for longer durations, the monthly bill won’t be as much.

Outdoor Weather Conditions

During high humidity and extreme heat, the air conditioner unit goes through a considerable amount of stress. This is because more energy is required to cool down the place. This difference in temperatures impacts the costs of running an AC, and you will consequently get higher power bills during extreme heat.

AC Installation & Maintenance

The proper installation of an AC unit is necessary for it to work efficiently. Additionally, suppose you do not get your AC system frequently maintained by professionals or do not regularly replace the furnace filter. In that case, your system will have to work harder to cool the room and end up consuming more power.

4 Most Common AC Types And Their BTU Capacities

The British Thermal Unit (BTU) is a unit of heat required to raise the temperature of 1 pound of water by 1 degree Fahrenheit.

The higher the BTU of a unit, the more power it can deliver.

1. Central Air Conditioners: 18,000 – 60,000 BTU

Central air conditioners use outdoor ducts to circulate air through them and provide cooling to your entire house. Typically its runs anywhere between three to seven months a year, depending on the outdoor climate. Central ACs consume a lot of energy to cool larger spaces and, therefore, result in higher electricity bills.

2. Mini Split Air Conditioners: 12,000 BTU – 48,000 BTU

Air conditioning system installation embedded on wall of building.

These ACs are small in size and serve individual rooms. Since they do not have ducts and a forced-air system, they reduce the energy loss. They can also spot cool, which further increases energy efficiency and reduces bills.

It is best to determine the size of the room to know which BTU AC you need. For instance, a 450-550 square feet area requires a 12,000 BTU AC for efficient cooling. Use this measure to find a unit proportionate to your space. That way, your AC won’t be underpowered, so you won’t be wasting energy.

3. Portable Air Conditioners: 5,000 BTU – 15,000 BTU

As the name suggests, these can be conveniently moved around the house with ease because you don’t have to install them or need ducts for usage. Furthermore, you can easily stow them away during the winter season. These units, however, have lower energy-efficiency with an EER rating of 10 or less.

4. Window Air Conditioners: 5,000 BTU – 20,000 BTU

These are small ACs that usually have an EER rating of above ten and an above-average energy-efficiency.

Lower BTUs are appropriate for small to medium-sized rooms, while higher BTUs are for larger rooms as they have more power, but they will increase your electricity bill due to more energy usage.

Cost To Run AC: Calculated By AC Type & Capacity

While you can use the formula given in the next section to calculate the cost to run an AC, you can decipher the estimated costs of using different AC types and their capacities in the table given below:

Central Air Conditioners

Rheem Premium Central ACYou should consider investing in central conditioning if you live in an area that is warm for most of the year and want to keep the entire house cool. If you have existing ducts and vents already installed, you will have to spend over $3500 to $4,000 for the AC to cool a 2000 square feet house. And if you don’t have that, be ready to pay double that amount to get the ductwork in place, plus an added annual maintenance cost.

Furthermore, these air conditioners consume a lot more energy because of their higher BTUs, which means that the monthly electricity bill would also be increased.

BTU Cost Per Day
(24 hr Usage)
Cost Per year
(24/7 Usage)
Cost Per Day
(6 hr/day)
Cost Per Year
(6 hr/day)
18000 $ 12.66 $ 4,621.7 $ 3.16
24000 $ 16.88 $ 6,162.2 $ 4.22
30000 $ 21.1 $ 7,702.75 $ 5.27
36000 $ 25.3 $ 9,243.3
48000 $ 33.8 $ 12,324.4
60000 $ 42.2 $ 15,405.5
Mini Split Air Conditioners

Ductless Aire Mini Split Air ConditionerA ductless AC system has an indoor and outdoor unit, but unlike a window AC, it only requires a small hole in the wall, making it less vulnerable to leakages. They are also very energy-efficient because of their inverter-driven compressor that regulates temperature.

However, according to the US Department of Energy, mini-split air conditioners cost around 30% more than central air conditioners and more than twice than a window AC. On average, these costs range between $2,000 to $14,500, depending on the BTU.

Other than that, since every room requires a separate unit, the overall labor cost for installing them is high.

BTU Cost Per Day
(24 hr Usage)
Cost Per year
(24/7 Usage)
Cost Per Day
(6 hr/day)
Cost Per Year
(6 hr/day)
12000 $ 3.84 $ 1,401.6
24000 $ 7.68 $ 2,803.2
36000 $ 11.52 $ 4204.8
48000 $ 15.36 $ 5,606.4
Portable Air Conditioners

lg-electronics-portable-air-conditioners-lp1017wsr-31_1000Portable ACs are easy to move around but can serve one space at a time. It is essential to get a size that is appropriate for the primary room. For instance, if you have a small 10×10 bedroom or 12×12 living room, it is best to get the small 8000 BTU AC. Furthermore, the higher the BTU, the higher the cost to run a portable air conditioner.

With that said, if you want to have efficient cooling across your house or office, this unit won’t be a good option. On the other hand, if you have to only cool down a small space, you will be quite pleased with its results.

BTU Cost Per Day
(24 hr Usage)
Cost Per year
(24/7 Usage)
Cost Per Day
(6 hr/day)
Cost Per Year
(6 hr/day)
5000 $ 1.68 $ 613.2
8000 $ 2.64 $ 963.6
10000 $ 3.38 $ 1,232
12000 $ 3.84 $ 1,401.6
15000 $ 4.8 $ 1,752
Window Air Conditioners

lg window acThese are small AC units that are fixed into the window sill. They are quiet and weigh only around 40 pounds, but these are costly, especially those with higher BTUs.

It helps to know the room’s size to figure out the BTU you need to get. Fewer BTUs will make your unit work harder, while higher BTUs might use more energy than you need.

Therefore, with knowledge of your exact room size, you can get a window AC that strikes a balance – it would neither be underpowered – nor overpowered.

Almost every air conditioning manufacturer produces the smallest 5000 BTU window AC, which requires a commonly installed electric grid of 115 V to function.

BTU Cost Per Day
(24 hr Usage)
Cost Per year
(24/7 Usage)
Cost Per Day
(6 hr/day)
Cost Per Year
(6 hr/day)
5000 $ 1.68 $ 613.2
6000 $ 2.02 $ 735.8
8000 $ 2.69 $ 981.5
10000 $ 3.36 $ 1,226.4
12000 $ 4.04 $ 1,473.3
15000 $ 4.8 $ 1,752
20000 $ 6.24 $ 2,277.6

Determine The Cost Of Running Air Conditioner: Calculate By Usage

Here is how you can compute the cost of electricity when running an AC.

1. Calculation Of AC Cost Per Hour (24/7)

Different air conditioner units have unique profiles for energy-efficiency. First, you need to figure out the amps that the unit draws, depending on its size and SEER rating. Then calculate the number of Watts and multiply that with the amps consumed. Divide this by 1000 to get the value in kWh.

Use the following formula to calculate the cost of running your unit per hour.

kWh * kWh unit cost = Per hour cost to operate an AC

2. Calculation Of AC Cost Per Day

To figure out how much it costs to run an AC per day, you can use the one-hour cost you learned to calculate above and multiply that by the number of hours you use your AC within a day. However, this cost is different for every household because many of them use thermostats.

3. Calculation Of AC Cost Per Month

The monthly costs of running an AC can be calculated using the cost-per-day and multiplying that by the number of days the AC functioned in a month. If your AC runs 24/7 across the month, simply multiply cost-per-day with 28, 30, or 31, depending on what month it is.

4. Calculation Of AC Cost Per Year

The yearly cost is not as straightforward to determine because you don’t use an AC throughout the year. Consider the months during which you run the AC to calculate your yearly costs. Your AC running costs will differ depending on the area you live in and the number of warm months you experience.

An easier way to find out the electricity cost to run an AC unit is by using our calculator to find AC costs for any period.

How To Reduce Your AC Electricity Consumption: Homeowner’s Guide

It’s a foregone conclusion that increased AC usage leads to augmented electricity bills. Therefore, here are a few tips to help you lower your AC’s electricity consumption.

1. Replace Or Clean The Filters

Clogged filters may not seem very problematic, but they can increase your power consumption. Blockages in filters are common due to dust that can eventually accumulate on motors and fans. This will reduce your system’s working capacity, making it soak up more power. Therefore, it is vital to replace or clean your AC filters frequently.

2. Control The AC’s Thermostat

Your AC’s thermostat setting is the most basic way to control how much electricity it uses. You can use the scheduled thermostat settings to set the AC on the ‘fan’ setting when nobody is in the room, which can significantly decrease your electricity bills.

3. Reduce Heat Sources

The warmer a room, the more your AC has to work to cool it down. Therefore, it would help if you kept appliances like televisions, computers, and lamps away from the unit. Otherwise, the heat produced will cause the AC to overheat and use more power.

4. Check Airflow Inside The Room

The AC will also provide inadequate cooling if it has dirty vents and a hindered airflow. Hence, always ensure consistent airflow in the room. Also, make sure that there are no blocked or contaminated ducts.

5. Make Sure That Air Ducts Are Properly Insulated

HVAC parts like ducts, pipes, and outlets need proper insulation, and any leaks need to be sealed to ensure that the AC doesn’t use extra energy to reach the exact temperature. A leak defeats the purpose of installing an AC because the cold air will continuously escape.

6. Remove Humidity From The Room With A Dehumidifier

It is essential to reduce your room’s humidity using a dehumidifier. It benefits the cooling process by reducing humidity that burdens the AC unit, ultimately reducing electricity bills.

7. Perform Regular AC Maintenance

People generally don’t give a lot of importance to regular AC maintenance, but it is essential to reduce your power bill. Regular cleaning of HVAC parts, replacing old ones, and repairing electrical connections will make your AC unit more energy efficient.

People Also Ask (FAQ)

Do Air Conditioners Use A Lot Of Electricity?

Typically, air conditioners use more electricity than any other household item. Appliances with heating coils can compete on this front; these include toasters and hair dryers.

How Much Will My Electric Bill Go Up When I Install An Air Conditioner?

While there will be a definite increase in your electric bill after installing an air conditioner, the eventual bill will depend on certain factors like AC size, type, how long you use it in a day, etc.

Is It Cheaper To Leave The AC On All Day Or Turn It Off When Not In Use?

It is cheaper to turn the AC off because letting it run even on low power will require energy.

Should You Open Windows With AC On?

It is recommended to close all the windows to keep the room cool and maintain the temperature when the AC is functioning.

How Much Does It Cost To Run An AC Overnight?

You can leave your AC on overnight provided you pre-program the resting temperature; otherwise, it will waste energy, and you will see a significant rise in your electricity bill.

Does It Cost More To Run A Heat Pump Or Central AC?

It costs more to run a central AC than a heat pump.

Does It Cost More To Run A Swamp Cooler Or Portable AC?

A swamp cooler is more energy-efficient and hence more economical than a portable AC.

Does It Cost More To Run A Fan Or Window AC?

A fan is much cheaper to run than a window AC.


Air conditioners are a blessing, especially for those living in areas accustomed to hot climatic conditions. However, it is essential to research the cost to run an air conditioner and the different types available on the market to figure out the one that will best suit your needs and budget.

And after buying one, it is crucial to learn how to use it efficiently so that your monthly electric bill doesn’t burn a hole in your pocket.

Josh M

My name is Josh and I am obsessed with the HVAC industry. I created this website to help HVAC techs of all levels get the best out of their heating & cooling systems. I have spent thousands of hours studying air conditioners, heaters and home air products so you can learn & buy with confidence. Learn more about the team here.