The Ultimate Guide to Calculating Central AC Size

The Ultimate Guide to Calculating Central AC Size

If you’re in the market for a new central AC, one of the most important decisions you’ll make is deciding on the size. Too small means your unit will struggle to keep up with the cool air demand on hot days. Too large means you’ll be paying for more capacity than you need, not to mention higher energy bills. So how do you calculate what size central AC is right for your home? Here’s a quick guide from the experts at Briggs Heating, Air Conditioning, and Electrical about what factors you need to consider.

What To Consider

When it comes to choosing an AC unit, size is everything. The square footage of your home is the primary factor you’ll need to consider, as this will determine how much cooling capacity you need. But this is just a starting point, below are some other factors you’ll need to consider:

Size of Your Home

The bigger the house, the larger the AC unit you’ll need. You’ll also need to factor in the height of your ceilings, the amount of sun exposure your home gets, and whether you have any rooms that are particularly hard to cool.

The Number of Rooms

More rooms generally mean more cooling capacity is needed. If you have a multi-story home, you’ll need to account for the fact that heat rises. So a room on the second floor will require more cooling capacity than a room on the first floor.

Number of Residents

The more people living in your home, the more heat will be generated. Additionally, any heat-generating appliances like computers and lights will also need to be taken into account. Your pets and other furry friends also generate heat, so be sure to factor them into your equation as well.

Geographic Location

Searching for something near you may never be quite as important as searching Google for “central AC near me.” Why? Well, because it’s important that your technician is familiar with the weather and environment in the area in which you live. The climate, whether hot and humid or cool and dry, will play a role in how much cooling capacity you need. At Briggs Heating, Air Conditioning, and Electrical, our expert technicians not only have an extensive knowledge of all makes and models of AC units, but we’re also quite learned in the  weather patterns and temperature extremes of our area and the localities surrounding it. With this knowledge, we can help you determine the perfect unit for your home.

The Energy Efficiency of the AC Unit

Not all AC units are created equal. A higher efficiency rating will mean that the unit will use less energy, and this will save you money on your utility bills. The other factor to consider is the maximum BTU output of the unit. This will determine how much cooling power the unit has, and it is important to choose a unit that is powerful enough to cool your entire home.


When calculating the size of the AC unit you need, it’s important to consider how often you’ll be using it and what time of year it is most used.

How to Calculate the Necessary Size

Now that you know what to consider, you can begin to calculate the size of the AC unit that is right for your home. There are a number of ways to do this, but the simplest way is to use a BTU (British Thermal Unit) calculator. BTUs are a measure of heat, and one BTU is equal to the amount of heat required to raise one pound of water by one degree Fahrenheit.

Another way to accurately calculate the size of the AC unit you need is to hire a professional HVAC contractor (like Briggs Heating, Air Conditioning, and Electrical) in order to find the right balance between cost and cooling power. We have the experience and know-how to quickly and correctly assess the cooling needs of your home. We will take into account all of the factors listed above, as well as any other relevant factors, to ensure that you get the perfect AC unit for your home.

We hope that by walking you through how to calculate what size AC unit you need, we’ve helped clear up any confusion and made the process a little less daunting. If you’ve been scouring the Internet for “central AC near me” and would like a free consultation from our experts, don’t hesitate to call us today!


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