How to Calculate the Square Footage of Your Home

Square footage of a house (GLA)

For most people, the gross floor area or gross living area (GLA) of a home is what they’re thinking when they hear “square footage.”

Here’s how to calculate your square footage:

    1. Sketch a floor plan of the home’s interior

      Draw each floor separately, and don’t include unfinished areas, patios, porches and exterior staircases.

    2. Break down the house into measurable rectangles

      The more rectangles the better. This takes the guesswork out of rooms or hallways that don’t have perfectly flush walls.

    3. Calculate the area of each section

      Multiply the rectangle’s length by its width to get the area in square feet. Write this number down in the corresponding space on your sketch.

    4. Add up the total area

      Sum up the square feet of each rectangle to measure the total square footage of the house. Round the total off to the nearest square foot.


4 Tips for Determining Square Footage

Here are few things to consider when preparing to measure the square footage or a property:

  1. 1. Draw A Floor Plan. Make a rough sketch of your property's floor plan. This will give you a sense of how you’ll add your calculations for each room together. This is an especially important step if you’re measuring irregularly-sized rooms with a square footage that involve a little more calculation.
  2. 2. Plan which rooms you will be measuring. When calculating square footage in any home, you should include the measurements of all the rooms in your house that are “finished,” enclosed by four walls, and are heated or cooled. You can measure spaces like garages, basements, or outdoor spaces for your own knowledge, but they should not be included in your square footage calculation.
  3. 3. Take extra care with irregularly-shaped rooms. All you need to do to measure the square footage of square or rectangular areas is multiply length times width. However many rooms in a home will be more oddly shaped. To determine the square footage of irregular rooms, measure the length of each wall using a measuring tape and record the dimensions on your floor plan. Then divide the shape of your room into regular shapes like squares, triangles, or circles. Calculate the square footage of each separate shape and add them together to get the total square footage of the room.
  4. 4. Remember the stairs. Include stairs in your home’s square footage calculation if you have them. Multiply the depth and width of one stair, then multiply that number with the number of stairs you have. Some appraisers will include the square footage of stairs twice, as they are considered a part of the floor plan of the floor from which they are descending and the floor to which they are descending. There are no standards governing whether you should include your stairs square footage twice.

When does a basement count as finished square footage?

The answer to this depends on where you live, as local governing bodies may choose to calculate square footage differently. But in Minnesota and western Wisconsin, if your basement has a finished floor, wall covering, ceiling and heat, then its square footage can be included in the total finished square footage of the house.

It’s also important to note that our local MLS, Northstar MLS, breaks out the total finished square footage of a property into above-ground square footage and below-ground square footage. If you are a buyer comparing homes and prices, you may want to pay attention to that breakout.

Keep in mind, some MLS guidelines don’t include below-ground square footage at all, even if the basement space is fully functional. If you’re in doubt, ask the listing agent what rooms and floors were included in their calculation of the home’s square footage.

How is square footage measured? 

To calculate square feet you multiple the room’s length by its width. For example, a space that measures 10 feet by 10 feet totals out to 100 square feet.

Length x Width = Area Ex. 10 ft. x 10 ft. = 100 square feet

While this may sound simple enough, it can be complicated measuring the square footage of a house due to odd-shaped spaces and living space gray areas.

“Here in North Carolina, square footage is calculated to the outer edge of the dwelling. So to properly calculate the square footage, an owner would need to calculate the area by multiplying the length by width, and including the wall thicknesses in their measurements,” explains Matt Harmon a North Carolina-based, state-certified property appraiser.

“For example, if a square house measured 20-foot by 20-foot when measuring to the interior walls, and the walls were 0.4-foot thick, then to calculate the area, you’d need to multiply 20.8 by 20.8 to find the exact square footage.”

However, if you’re selling a condo in a multi-family unit — meaning that you only own the interior space, not the exterior building — you would only measure square footage from interior wall to interior wall.

Finished basements and attics do not add to the primary square footage

The square footage of a finished basement that is below grade (underground) adds less value than the square footage of above grade living space.

So if your home is 2,000 square feet, and you have an additional 1,000 square-foot finished basement, you cannot claim to have a 3,000 square-foot home if your local area values basement spaces at a lower dollar amount than the rest of the house.

In this instance, you would list your home at 2,000 square feet and then include the additional 1,000 square feet of living space in your finished basement in the listing notes.

The same is true of finished attic spaces. If the space has sloping roofs, inadequate windows, and forms of egress, then the area may not count towards your overall square footage.

To determine if your space makes the cut, consult an appraiser or an experienced real estate agent.

Source: (Point3D Commercial Imaging Ltd. / Unsplas
Source: (Point3D Commercial Imaging Ltd. / Unsplash)

Why Is Square Footage Important?

Square footage is important in real estate because it is the clearest representation of the total area of livable space in a homeowner's property. Here is an overview of the practical reasons that square footage is important.

  • 1. Home value: Square footage is one of the variables factored into setting the listing price or determining the fair market value of a house. If you order an appraisal for your new house to determine its fair market value, the appraiser will factor the square footage of this house to similarly-sized homes in the area.
  • 2. Securing a mortgage: Most mortgage lenders will require homebuyers to get a home appraisal before granting them a loan to protect the lender from promising more money than the house is worth. If your appraiser finds that a home is worth less than it is listed for—potentially because of a square footage discrepancy—the buyer may not get a loan for the house unless the listing price is adjusted to affect the appraisal value.
  • 3. Property taxes: Assessing your home and measuring the square footage can help gauge whether a homeowner is paying too little or too much in property taxes. Your property’s square footage directly impacts the assessed value of the house, which influences property taxes you’re required to pay.

Do insurance agents calculate square footage the same way?

You may also wonder how square footage is calculated or used within a homeowner’s insurance policy. We reached out to Scott Teece, managing producer at Edina Realty Insurance, to get the details.

When creating an insurance quote for a client, Edina Realty Insurance typically pulls from the MLS listing to ensure they are assessing the same square footage as indicated in the property records. But while homebuyers care mostly about finished and unfinished square footage, insurance agents take special notice of a different breakout — above ground square footage and below ground square footage.

“When offering coverage to a homeowner, we calculate the total replacement cost of the property,” explains Teece. “Both above ground and below ground square footage are factored into that calculation, but the cost to replace the above ground square footage is typically somewhat higher. That’s because, for example, if a catastrophic event like a tornado or fire should occur, you’d likely have to reframe the first floor and above, but not the basement.”

In other words, a 2,000-square foot house without a basement would likely have a higher replacement cost than a home with 1,000 square feet of above-ground living space and a basement sized at 1,000 finished square feet.

When Teece and the Edina Realty Insurance team draw up a homeowner’s insurance quote, they rely on the MLS’ breakout of above ground square footage and below ground square footage to make their assessment.

Have additional questions? Contact the team at Edina Realty Insurance for more information or a personalized quote.

What Is Included in the Square Footage of a House?

Only usable space is included in your home’s square footage. Typically, usable space is defined as areas in your home that:

  • Share the same heating and cooling system as the main house.
  • Are located above ground.
  • Conform to your home’s architectural standard.
  • Are finished and adjoining.

Looking at it that way, it’s pretty clear that rooms like your kitchen, living room, bathrooms, and bedrooms are part of your square footage﹘as long as you don’t have to pass through unfinished spaces to reach them. The same goes for hallways, stairways, and closets. Enclosed patios may be included if they have four walls and a roof and use the same heating as the rest of your home.

A finished attic can also be part of your square footage, but like enclosed patios, it usually has to share your home’s heating and cooling system. Plus, it may need a certain amount of headroom to count.

Garage and basements aren’t usually included in the square footage of a house. This is often true even if the basement is finished because it’s below ground level. However, some states do allow you to include finished basements when they have safe ways to enter and exit. Detached structures such as sheds are also generally excluded from the calculations.

Do Closets Count as Square Footage?

Closet areas are included in the square footage of a home, but only when they are in the main home. Closets in areas that aren’t considered usable space, like basements, aren’t included. When you calculate the square footage of a house, treat each individual closet as if it were a room and add it to your total.

How to Calculate Square Footage

Square footage is area expressed in square feet. Likewise, square yardage is area expressed in square yards.  Square meters is also a common measure of area.

Assume you have a rectangular area such as a room and, for example, you want to calculate the square footage area for flooring or carpet.

The way to calculate a rectangular area is by measuring the length and width of your area then multiplying those two numbers together to get the area in feet squared (ft2). If you have on oddly shaped area, such as an L-shape, split it into square or rectanglualar sections and treat them as two separate areas. Calculate the area of each section then add them together for your total. If your measurements are in different units, say feet and inches, you can first convert those values to feet, then multiply them together to get the square footage of the area.

Convert all of your measurements to feet

  • If you measured in feet skip to “Calculate the Area as Square Footage”
  • If you measured in feet & inches, divide inches by 12 and add that to your feet measure to get total feet
  • If you measured in another unit of measure, do the following to convert to feet – inches: divide by 12 and that is your measurement in feet – yards: multiply by 3 and that is your measurement in feet – centimeters: multiply by 0.03281 to convert to feet – meters: multiply by 3.281 to convert to feet

Calculate the Area as Square Footage

  • If you are measuring a square or rectangle area, multiply length times width; Length x Width = Area.
  • For other area shapes, see formulas below to calculate Area (ft2) = Square Footage.

How To Measure Square Footage Of A House In 3 Steps

To calculate the square feet of a house, you will need to determine each room’s area and add it together. It sounds easy, right? We’re going to try to keep it that way as we walk you through the process. Gather a few tools before getting started:

  1. Tape Measure

  2. Notepad and pen/pencil

  3. Calculator

You may also want someone to assist as you measure, especially in larger rooms. While it all depends on the shape of your house and the complexity of your floor plan, sometimes it’s a good idea to start this endeavor with a helping hand. When you are ready to get started, there are three steps to follow:

  • Measure the length and width of each room and hallway in your house.

  • Multiply the length and width of each room separately, which you can write down before your final calculations.

  • When you are done measuring and multiplying, add the area of each room together.

Square Footage Of A House Example

For example, pretend you live in a ranch home in the shape of a rectangle. The length of the house is 70 feet, and the width is 50. This means to calculate the square footage, you will multiply 70 by 50, resulting in a final calculation of 3,500 square feet. Of course, not every home is a perfect rectangle — making it more time-consuming to get accurate numbers. That’s why going room by room is often the most practical method. With the proper measurements and some addition, you can still calculate the square footage of your home.

How Do Appraisers Measure Square Footage?

Appraisers measure the square footage based on the interior parts that get hot and cold. That includes closets, bedrooms, bathrooms, hallways, kitchens, living areas, finished attics, and enclosed patios. All unfinished areas, airspaces, open patios, or vaulted rooms are not included when calculating the square feet of a house. Storage spaces, a guest house, or a pool house will also be left out of measuring the square footage of a home.


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