How Much Does It Cost to Run a Window Air Conditioner? [2025 Data]

Typically, the cost of a central air conditioner is higher than the average cost to run a window AC unit, which is $0.06 per hour to $0.88 per hour at the national average of $0.13 kWh. That price assumes that the homeowner uses their window unit for eight hours a day. The actual cost of running a window air conditioner will depend on BTU, hourly usage, kWh, room size, and comfort level. In this guide, discover how window units affect your energy bill, when to hire a window AC repair pro, and what factors influence the cost to run them.

Average Cost to Run a Window Air Conditioner By State

The cost per kilowatt hour or kWh varies by state and can impact how much it’ll cost you to use a window unit. Here are some averages homeowners across the country see when using one of these units. These factors assume an 8,000 BTU window unit for 24 hours with an EER of 10. 

Price to Run a Window AC Unit Per Hour

Here’s the cost to run a window AC unit every hour, at the national average of $0.13 kWh.

Price to Run a Window Air Conditioner per Day

Here’s the cost homeowners can expect to pay to run their AC unit at $0.13 kWh and for eight hours a day. 

Price to Run a Window AC Unit per Month

At an average of $0.13 kWh, for eight hours a day, and 30 days out of the month, here’s how much it’ll cost you to run your window AC unit:

Cost to Run a Window AC Unit by Hourly Usage

The number of hours you plan on using your window unit per day plays a major role in how much dough it’ll cost you. Here’s a look at some average prices of running a window AC unit by hourly usage with a $0.13 kWh:

6 hours

• 5,000 BTW: $0.39/day

• 8,000 BTU: $0.51/day

• 10,000 BTU: $0.70/day

• 12,000 BTU: $0.85/day

• 15,000 BTU: $1.17/day

10 hours

• 5,000 BTW: $0.65/day

• 8,000 BTU: $0.85/day

• 10,000 BTU: $1.17/day

• 12,000 BTU: $1.43/day

• 15,000 BTU: $1.95/day

12 hours

• 5,000 BTW: $0.78/day

• 8,000 BTU: $1.03/day

• 10,000 BTU: $1.40/day

• 12,000 BTU: $1.71/day

• 15,000 BTU: $2.34/day

16 hours

• 5,000 BTW: $1.04/day

• 8,000 BTU: $1.37/day

• 10,000 BTU: $1.87/day

• 12,000 BTU: $2.28/day

• 15,000 BTU: $3.12/day

24 hours

• 5,000 BTW: $1.56/day

• 8,000 BTU: $2.05/day

• 10,000 BTU: $2.80/day

• 12,000 BTU: $3.43/day

• 15,000 BTU: $4.68/day

Factors that Influence the Cost to Run a Window Air Conditioner

Apart from BTU, kWh, and hourly usage, other factors play a role in how much your window unit will cost you; let’s look at some of them below:

• Comfort level: Some people prefer to keep their home cold and use extra layers for warmth, while others prefer their home to stay on the warmer side. Even with an appropriately sized unit, how cool you want your room to be will determine how long you use it and how much it’ll cost to run it.   

• Amps: The number of amperes or amps that a window unit uses is based on its BTU and the more amps required, the higher your bill will be.  

• EER: The Energy Efficiency Ratio (ERR) or Combined Energy Efficiency Ratio (CEER) measures how efficient your window unit is using your energy. If your unit has a higher EER, it’ll require less energy to cool your room. 

• The number of units: The more window units you have, the more it’ll cost each month to run them. 

How to Save Money When Running a Window Air Conditioner?

When trying to save money with a window air conditioner unit, it depends on your comfort level and energy efficiency. While some homeowners like to use window units throughout the day, most only need it until it’s cooled off their home. 

So, the best way to save money when using your window unit is before you start using it at all—during the purchasing phase. See how much space you want to keep cool, then see the recommended size for that space. By doing this initial research of the size and type of window air conditioner you need, it’ll be able to cool off your room efficiently, so you’ll only need it on for a few hours a day, instead of all day, if that’s what you prefer. 

How Can I Save Electricity with My Window Air Conditioner?

The key to saving electricity with a window AC unit is to keep it well-maintained. When AC units develop grime and debris buildup, they work harder to cool your space, using more electricity and increasing your monthly utility bill. Clean your window AC unit frequently and remove debris quickly. As part of your maintenance routine, clean the unit’s evaporator coils and replace air filters.