How to Calculate the Square Footage of Your Home


Ben Mizes


July 10th, 2019


Calculating the square footage of your home can seem daunting. A top-rated agent can help you get your home ready to sell and measure square footage.

Updated July 10th, 2019

There's a lot to consider when selling or buying a home. One of the most important factors that a buyer should understand when evaluating properties is the property's square footage.

Because there is no exact science to measuring square footage, an accurate assessment is even more important, as square footage can be one of the leading factors that drive the value of a home.

We highly recommend the help of a top agent for this integral step in the sale or purchase of your home.

What is The Math Behind Square Footage?

To begin with, a good framework for buyers and sellers alike is to think of each room in your house as a rectangle. Assuming you have a rectangular area will allow you to use the square footage calculation, length x width = (ft2).

If you have an oddly shaped area, such as an L-shape or trapezoid, split it into square or rectangular sections and treat them as two separate areas. Not every space is linear, but you can still determine the square footage of an area by dividing it into area shapes and calculating each shape's individual area.

Even if it's difficult to measure certain areas because of carpeting or tiling instead of hardwood flooring, try to get as close to the right number of feet, so your can get an accurate measurement.

Here is a simple, five-step process for measuring the square footage of your home:

  • Measure the length of the room.
  • Measure the width of the room.
  • Round up to the nearest six square inches.
  • Multiply each space’s length x width.
  • Add up the measured sum of each room to find the total square footage. Be sure to round off to the nearest foot.

A square footage calculator can be a useful tool in calculating square footage of a room or home. Gather useful tools like a tape measure from your local home improvement store before you measure.

Get help from a top-rated, full-service realtor!

Work with Clever, get expert guidance, save thousands.

Which rooms should you measure?

After you understand the math behind square footage, you then must understand which areas to include in your overall calculation. Do not include garages, patios, porches, external staircases, or other rooms without first knowing the specific requirements for each of them to be included. A home's building plans or blueprints are another great resource for buyers or sellers. Contact your local permit agency or records office to get this information.

Here is a list of rooms that may add to a home’s square footage:


A home’s basement may be considered when calculating the livable square footage of a home. As a general rule, any structure below grade, or underground, should not be included in the total area. These standards will vary by stage along with the definition of "below grade." The only allowable space for walkout basements is the above-ground square footage.

Whether a basement is finished has little to do with its inclusion in the home's square footage. Basements can still add value to the home and are often showcased online. On average, finished spaces are in higher demand than a space that needs renovation.


To include an attic in a home's square footage count, it needs to be finished and include at least seven feet of clearance space. Buyers will commonly find attics advertised in the home listing even when the space is not considered livable.


If a porch is covered and enclosed, sellers can include them into the square footage count. Heating and cooling systems on porches must also be the same as on the rest of the home. A good example of a covered, enclosed porch is found is a sunroom.

Outbuildings and Extras

Garages, outbuildings, pool houses, and external guest rooms can also boost a home's value. Despite this, you should not include these areas in the square footage calculation unless a connection exists with the main house. As a buyer, consider these “bonus” rooms.

Be Honest

No matter which method you use to determine the square footage of your home, remember to be accurate and honest. The size of a home is a key factor for home buyers, and a large discrepancy could hinder or lose your sale. As a seller, it is up to you to make sure that your house is being represented correctly.

How can a real estate agent help?

Considering the importance of square footage, first-time home buyers should not be afraid to reach out for help. There are appraisers that specialize in valuing homes in most areas.

For sellers without an agent (commonly known as FSBOs), a well-qualified appraiser is essential for accurately advertising the property. Seasoned real estate agents are familiar with a home's spacing and can often estimate sq ft without a tape measure.

You can find a final source of information in the city's building department, where home builders must submit square footage in their documentation for plans and permits.

Clever has knowledgeable and experienced full-service agents all over the country who would be happy to help answer your questions, including helping you calculate the square footage of a house. They will sell your home for a flat $3,000 or 1% over $350,000. Say goodbye to traditional real estate commissions and contact us today!

FAQs about Square Footage

What is included in the square footage of a house?

Most spaces in the home are included in its square footage, including stairways, hallways, and closets. Finished attics will be included if they have at least seven square feet of clearance. Covered and enclosed porches can also be included if they are heated using the main HVAC system. However, basements or other below-grade spaces are not counted toward a home’s Gross Living Area (GLA), nor are any areas that require you to leave the main finished area of the house, such as garages, guest houses (casitas), or pool houses.

How does an appraiser determine the square footage of a house?

Most appraisers use a simple technique to determine Gross Living Area (GLA). They measure the exterior of the home. If the exterior measures 30 feet by 40 feet and is one story, the home contains 1200 square feet. This includes all closets, hallways, stairwells, and even wall space since its starting from the exterior. The appraiser will also take into consideration other finished spaces not included in the square footage into their valuation, but usually at a lower price per square foot than the main house.

Does square footage of a house include all floors?

Square footage of a home includes all above-grade floors, usually excluding basements. An attic can be included if there are at least seven feet of head clearance and HVAC.

Are hallways included in square footage?

In the Gross Living Area (GLA) calculation, an appraiser (or someone else) calculates square footage by measuring from the outside, so wall space, stairwells, and even hallways are calculated in the total square footage.

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