Tips to Calculate Square Footage | 14 Important Facts

Tips to Calculate Square Footage | 14 Important Facts

Calculate Square Footage

Understanding how to calculate square footage of a home is more important than you think. Whether you are buying or Tips to calculate square footageselling, knowing how many square feet of the property will provide an understanding of the size of the home. Even if you are buying new construction, it is important to understand the size of the home.

When you are selling your home, not only is important to have the home ready to sell and staged but understanding the square footage is another important factor. defining the living square feet will enable you to better compare it to other homes. If you are buying a home, it is never a bad idea to check the information you’re being told. There are many sources that a seller may obtain square footage from and that includes an appraisal, tax records, assessor, and the MLS. However, calculating the footage of a home may not be as straightforward as you might imagine. If in doubt, and it is important to you, the buyer should have the home measured by an architect, draftsman, or an appraiser to determine the actual square footage.  Measuring and understanding the square footage is an important factor in the home buying process when you calculate square footage.

Do You Have to Hire a Professional to Measure Square Footage?

Calculating the living space is something you can do yourself for your own home.  It can appear to be a simple case of adding the sum of the dimensions of the rooms together, but things aren’t as easy as that. Not every part of your home will count as living square feet, you need to be aware of what to include and what to miss out.

When you are buying a home and obtaining a mortgage, you will be getting a home appraisal. It is an important criterion in the home buying process. All appraisers utilize a method to determine the square footage of the home.

How to Calculate Square Footage

There isn’t a universally accepted standard to calculate square footage of a home. There are some sets of procedures to include and what to ignore when determining the living space of a home.

Calculate Square FootageHeight

The height of a room will determine if it can be included in the square footage calculations. A room needs to have a ceiling height of at least 7 feet to count as a livable space generally. The room must be a finished area, and if there are obstructions like beams or ducts, the height requirement is lower at 6 feet 4 inches under those features.

For homes with sloped ceilings, half of the room must meet the 7-foot requirement. The size of the room can include any area with a ceiling height of 5 feet or more. Only when the room’s floor area has been established under these rules can you assess if half has a height of 7 feet or more. This information is according to The American National Standards Institute (ANSI).

Living space is calculated when determining the square footage of a property. In a single-family house, the gross living area or GLA includes the living space that is above the land-line. In order to be calculated as a living space, the area needs to have lighting, heating, and ventilation.  and has heating, lighting, and ventilation.

Finished Rooms

Normally, unfinished parts of the home would not be included in any calculations for living square footage when you calculate square footage. If you do have rooms that aren’t finished, these can be mentioned as bonus areas in listing descriptions. They do add space but not actual


Garages shouldn’t be included in the total living space. This still applies even if the garage space is finished. This is due to the area not being on the same level as the rest of the home. You will likely have to take a step down from the main living area to enter the garage, so they generally aren’t on the same level.


The same situation applies to basements as with garages. They can’t be included in the overall measurements of the home even when they are properly finished and useable as a living space. They can still be mentioned separately as an additional part of the home, but don’t meet the ANSI’s guidelines.

Attic Space

As long as the attic is finished and meets the height rules, it can be included in the total area of the home. It does need to have at least half of the floor space with a ceiling height of 7 feet or more.

Covered Porches

Areas like a California Room can be included in the measurements as long as they are finished. The area should be heated with the same system that the rest of the home uses, as well.

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Room Additions

If the home has a room addition, this can be added to the overall living space. It does need to be attached to the main part of the home and be finished. The connecting space, like a corridor or staircase, also has to be finished for it to count under the rules. If the room addition is not permitted, it may not count towards the square footage at all. Be sure to check the permit history of a home as part of your due diligence in the home buying process.


Sunrooms do add value and many homeowners do add them to their home. I have been asked if the sunroom counts as living square footage. The answer to this question is, it depends. One of the contributing factors an appraiser will consider is if there is HVAC in the sunroom. Be sure to consider that and fully investigate before investing in a sunroom.


Although many homeowners would like to count the square footage of a garage as living square footage, it is not. An appraiser How to Calculate Square Footagemay measure the size of a garage and include it in a floorplan,  but the square footage does not contribute to the living square footage of the home.

How to Disclose Square Footage

When you are selling your home, your real estate agent will look up your property to calculate square footage in the tax records of the home.  If a seller has a recent appraisal of the home, they may choose to use that square footage in the MLS or multiple listing agents. A seller must disclose to the buyer the source of the square footage whether it is from a builder, assessor, appraisal, or tax records. It is also recommended to have your agent include in the MLS, buyer to verify square footage if a factor in the purchase. Even if you are selling your home as-is, it is imperative that you disclose the square footage of the home.

Making Sure Your Home is Sustainable

If you are looking to determine the amount of insulation your home needs, the calculation is slightly different, however, when you calculate square footage.  Understanding the amount of insulation a home needs is different from the livable space of a property. To ensure you have the right amount of insulation in your home, you should consult with a professional. Different parts of the country are going to have different requirements due to the climate. So while calculating square footage for insulation of o a home is different, it is beneficial to ensure the home has adequate insulation. The home can then be marketed as green or eco-friendly.

Benefits of Knowing Accurate Square Footage

There are benefits of knowledge and calculate square footage as this is information that your real estate agent can include with the marketing of the home. Also, it shows to a buyer that you are serious about disclosing the material facts about the home and have taken the extra step to provide this information to a buyer. Additionally, if the square footage is a positive seller factor, the listing agent may include this information in appealing listing descriptions written about the property.

Final Thoughts

If you know how to correctly calculate square footage or assess the size of either your home or one you are looking to purchase, you will be in a better position when it comes to a home transaction. You could sell your home for more, or discover when details of a home’s footage are incorrect if you take the trouble to check it yourself.

About the Author

Top Newport Beach CA Realtor Sharon Paxson with Newport Beach Real Estate has written the article “Tips to Calculate Square Footage in Your Home”.

Sharon has been specializing in residential real estate since 2005 throughout Newport Beach CA and the surrounding area. Whether you’re looking to buy, sell, or rent she will guide you through the entire real estate transaction. If you’re ready to put Sharon’s knowledge and expertise to work for you call or e-mail her today.

Areas of service include Corona del Mar, Huntington Beach, Newport Beach, Newport Coast, and more coastal Orange County communities.

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Sharon Paxson is a full-time REALTOR® with EQTY | Forbes Global Properties and has been specializing in residential real estate throughout the Newport Beach area since 2005 assisting Buyer’s, Seller’s, Landlords, and Tenants with their real estate needs.

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