The Foolproof Way to Calculate Your Home’s Square Footage

If you’re in the market for a new home or it’s time to list your own, you’ve probably come across the term “square footage” and may even need to measure the square footage of your home.

Ahome’s square footagerefers to its gross living area (GLA). The GLA is essentially the total of all living areas in a home. It’s related to the home’s price, but there are lots of factorsin an appraisalthat determine a home’s price per square foot. And just looking at this number leaves a lot to the imagination.

Factors that influence a homes price per square foot include:

• Interior finishes
• Amenities such as a pool, deck or porch, garage, wine cellar, sauna, etc.
• Updates to the bedrooms, kitchen, bathroom, etc.

The American National Standards Institute (ANSI) lays out standards for calculating square footage, which have beenadopted by Fannie Maeand must be used when appraisers are calculating square footage for a Fannie Mae loan. While you can calculate square footage from the interior of the home, appraisers actually measurefrom the exteriorand then analyze the interior to come up with the final calculation.

There are two methods for calculating square footage, but to get the most accurate measurements, you should use both and compare.

To measure the exterior of the home, sketch the home’s footprint and then measure the length of each wall in feet. Appraisers using the ANSI standards must use a computer generated sketch of the home.

Once each wall is labeled, break the space down into rectangles and then multiply the length and the width. If there are other shapes to consider, you can use asquare footage calculatorto help. Add up all the totals to come up with the final calculation.

To determine the square footage using this method, take the measurement of each room by measuring the length and the width in feet and then multiplying the numbers together. For irregularly shaped rooms, you can use a square footage calculator.

Add up all of the totals to come up with the final calculation. Be sure to measure all finished spaces that are heated and cooled, including closets. Whenaccounting for staircases, count them toward the square footage of the floor from which they descend.

The total of the exterior calculation won’t match the interior calculation exactly because it includes the exterior and interior walls, but it will allow you to subtract any space that doesn’t count toward GLA.

• Unfinished areas including the garage and attic
• Finished areas with a ceiling height less than 7 feet for 50 percent or more of the area
• Finished areas with a ceiling height less than 5 feet
• Accessory dwelling units including pool houses, guest houses, and sheds
• Areas that are heated and cooled differently from the rest of the home — or not heated and cooled at all
• Two story foyers only count toward the square footage on one floor

To accurately calculate square footage, the best method is to hire a licensed appraiser. It will probably cost less than $200, and you’ll be assured that they’re using their professional knowledge and experience to get the most accurate measurement.

You can also measure the home yourself using the same method they use. If you feel like there’s a discrepancy between their number and your number, you can discuss any inconsistencies to make sure you have the most accurate calculation. If you’re looking for an extra hand, your real estate agent can also help you measure.