Square Feet Simplified: How To Measure Every Room in Your Home

By Margaret Heidenry

Whether you’re selling or looking to buy, it’s crucial to understand how to calculate the square footage of a house. There’s a huge difference between a home that’s 400 square feet (tiny) and one that’s 4,000 (McMansion), and not just in terms of how much space you’ve got to stretch your legs.

A home’s square footage is a key element in determining the price of a home you’re trying to buy or sell, how much you’ll pay in taxes if you live there, and what kinds of renovations are possible in your future. Plus, a home’s square footage can be surprisingly subjective.

Since most people don’t have a square foot calculator in their back pocket, here’s what you need to know to ace any square footage calculations that crop up in your future.

How to calculate the square feet of a room

To calculate the square footage of a simple room without any funny shapes, break out your measuring tape-or a laser measure-to get its length and width. Multiply the width by the length and voila! You have the square footage.

In the example above, the living room is 20 feet wide by 13 feet long. The equation (20 X 13) brings you to the total square footage: 260 square feet.

Calculating the square feet of a kitchen

Calculating the square feet of a kitchen may seem difficult given how much of the area space is occupied. Oven, refrigerator, pantry-there’s a plethora of features that make measuring wall space a bit more difficult.

Best advice? If the room shape is a true square, then you can measure around the features, calculating the width and length despite not having flush access to the walls. If the room shape is more irregular, you’ll need to break the room down into small “boxes” or spaces, calculate the square footage of those boxes, and add them together.

Calculating the square feet of a bathroom

Bathrooms are the spaces that arguably have the most immovable features, like the tub, shower, sink, and toilet.

But the same rules apply with the bathroom as the kitchen. As long as your space is a square, you can measure across these features to arrive to the square footage of a bathroom.

Calculating the square feet of a basement

Basement size varies depending on your home. Typically, it runs the full length of your home, so calculating the square footage of your basement will follow the same equation as calculating the square feet of your house.

How to calculate the square feet of a house

While measuring a single room is no big deal, calculating the square footage of an entire home is a bit more difficult-but not impossible.

While homes can initially seem “daunting to measure,” admits Mario Mazzamuto of SF Bay Appraisal, if you think of your home as “a collection of small boxes,” the task becomes much simpler.

Look at the layout of your home and measure each room or “box” individually. If a room has an outcropping, break that area down into a smaller box to be factored in.

Let’s take a look at this floor plan of a sample condo. Using the singular room equation from above, we can determine that the living room, bedroom, bathroom, and hallway are 500, 400, 200, and 100 square feet, respectively. By adding those calculations together, we can conclude that the condo is 1,200 square feet total.

How to find the dimensions of your house

If you’re looking for the dimensions of your own property, measuring each room individually will get you the information you need.

But if you’re buying a home and you’re interested in the dimensions of a home, there are several online resources you can use. First, listing websites will provide dimensions and square footage information for all properties listed.

You can also find this information by visiting the property assessor’s office, either in person or online, to access records for a house or plot of land. Lastly, you could use map services like Google Maps to estimate dimensions. While this method won’t necessarily yield the most accurate measurements, it can be helpful to buyers to look at the property from an aerial view to get a good idea of the space.

Odd shapes and using a board floor calculator

Understanding the square feet measurements of your home or a singular room is essential when planning any renovations, particularly flooring.

If you have a round kitchen and a triangular rumpus room, fear not. Just check out vCalc’s handy calculator, which will tell you how to calculate square feet no matter what polygon’s thrown your way. Once you choose a shape, the calculator will prompt you for the measurements needed to compute square footage.

Having the square feet numbers in hand will also make it easier to use a board floor calculator, which will help you price out the cost of materials per board foot. A board foot measurement equals 12 inches wide, 1 inch thick, and 1 foot long.

If you know the square feet of your room, let’s say your dining room, you can use a board floor calculator to determine how much it would cost to add hardwood floors. You’ll plug in the square feet, then multiply the board feet per piece by the number of pieces needed for the project

When the numbers don’t match up

Now that you know how to calculate the square footage of a home, it’s time to bust your bubble with a big caveat: A square footage calculation is surprisingly subjective based on who’s doing the measuring. For instance, you measured the actual, livable square footage between the interior walls. But many architects use their own square foot calculation method, measuring the square footage from the exterior walls.

This explains why there are often discrepancies between your square foot calculations and those of a real estate agent, builder, or other sources.

“Many MLS services require a listing’s square footage to come from a specific source,” says Robin Kencel of Connecticut’s Stevens Kencel Group.

So while you can make your own estimate, you may need to hire a certain professional to come up with a number that can be used on your listing; check with your real estate agent or town’s building department to determine who that is.

As a general rule, “the square footage extends through the Sheetrock and framing to the exterior of the wall,” says Mazzamuto. Generally, to do the same for your measurements, add 6 inches per measurement.

Understanding the price per square foot

Once you know the square footage of your home, you can start to evaluate the value of your house. The price per square foot is the general metric used by real estate professionals when determining a listing price, along with location, condition, and the house’s age.

The math is fairly simple: If you know the current list price, you divide that number by the home’s total square footage to arrive at the home’s price per square foot. For example, a 2,000-square-foot home that’s listed for $500,000 comes out to $250 per square foot:

$500,000 ÷ 2,000 = $250

The current median price per square foot in the U.S. is around $233, according to the most recent data from the Federal Reserve Bank of St. Louis.

Dina Sartore-Bodo contributed to this report.

Margaret Heidenry is a writer living in Brooklyn, NY. Her work has appeared in the New York Times Magazine, Vanity Fair, and Boston Magazine.

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