A tape measure and a hammer beside the wooden outline of a house

Looking to get an accurate measurement of your home's square footage? Here's how to do it quick and easy.

Whether you're buying a home, selling a home, refinancing a home, or just browsing around, one crucial element of any of those processes is accurately calculating the square footage of the property in question. This process isn't as difficult as one might expect, even for those who weren't paying attention in high school math class. For a number of reasons, it's an excellent idea to learn how to measure the square footage of your home or a home you’re looking to purchase.

Why does square footage matter?

A ladder and paints in a house under renovation

Learning to calculate the square footage of a home can save you hundreds of dollars.

The square footage of a home is a deciding factor in the value of it. Generally, the higher the square footage, the higher the price for the property. Conversely, the smaller the home, the smaller the price tag.

Also, learning to calculate the square footage of a home can save you hundreds of dollars. By performing this simple task yourself, you can save on the cost of hiring a professional to do it. You can also ensure that the job is done accurately and confirm the measurement in the description of a “for sale” listing. Although calculating the measurements yourself can give you peace of mind, expect to pay a professional if you’re listing the home on the MLS as many of these services require these calculations to be verified by a specific source. 

Knowing how to calculate the square footage of a home is also useful if you’re renovating or refreshing your home. Knowing the square footage of the house or a single room is immensely helpful in determining how much paint to purchase or how much flooring or tile to buy, among other supplies.

Although measuring the square footage of a house can be a simple task, in reality, there is no established standard for the process, so results can vary depending on the person’s technique. This is another reason you may want to do it yourself—to double-check someone else’s work. If the task is done poorly or inaccurately, it will likely undermine the value of your house. 

Calculating the Square Footage of a Home

Closeup on hands measuring the blueprints for a house

This task can seem daunting, but if taken step-by-step, it's relatively simple.

Although there’s no set standard for calculating the square footage of a residential home, most people go about it the same way. They look to measure the “Gross Living Area” or the GLA, which is the gross floor area of all of the indoor rooms combined. This task can seem daunting, but if taken step-by-step, it's relatively simple.

To begin your calculations, sketch a rough layout or blueprint of the home you want to measure. You’ll want to sketch out all of your rooms, and non-enclosed spaces such as hallways, entryways, and nooks. Any enclosed space inside of the exterior walls counts as part of the home, including sunrooms and garages.

You’ll want to look at the entire home as a collection of spaces, or boxes to measure. If a room isn't a perfect square or rectangle and includes an outcropping, just break down the area into smaller boxes, for easier measuring. 

To calculate a simple square or rectangular room, simply use a measuring tape (or other measuring device) to measure the length and the width of the room. Simply multiple the width by the length to calculate the square footage of the room.

For example, if a room is 20 feet wide by 15 feet long, then the room is 300 square feet in total (20 x 15 = 300.) These calculations are pretty straight forward if the rooms in your home are four-sided, i.e. square or rectangular shaped. Thankfully, most rooms in a house are. But you may be wondering what to do if your home has, say, a circular sunroom or a triangular kitchen. These uncommonly shaped rooms are a little more difficult to calculate but can be done.

We recommend using a free online tool to calculate circular, triangular, quadrilateral, or oval-shaped areas. One such tool is the square footage calculator at vcalc.com.

Using an Online Calculator

Closeup up on a man wearing gloves while using a tape measure on a wall

You can use an online calculator to determine the measurements you need to plug in.

To use the online calculator, you must first identify the shape of the room you’d like to measure. It'll be either a four-sided shape (a square or rectangle), a circular shape (a circle or ellipses), a three-sided shape (a triangle), or a many-sided room (a polygon.) 

Once you’ve identified the shape of the room, you can use the online calculator to determine the measurements you need to plug in. For example, if the shape of the room you are calculating is a triangle, the online calculator will have you simply plug in the base and height measurements, and then will calculate the area for you given the mathematical equation for finding the area of a triangle (A = 1/2 x b x h).

These online calculators prove to be very useful as you won’t need to memorize or relearn those sometimes complicated formulas you forgot long ago from high school geometry.

Take the Final Number With a Grain of Salt

Closeup on a hammer, a tape measure, a ruler, and nails on a wooden table

Try not to worry if your calculations don’t match up exactly to what the builder, realtor, or architect has calculated.

Once you’ve calculated the square footage of every room in your house, along with open spaces such as hallways and nooks, you can simply add them together to calculate the square footage of the complete house.

Try not to worry if your calculations don’t match up exactly to what the builder, realtor, or architect has calculated. Some people calculate the square footage of a home by measuring from the exterior walls, rather than the interior. This discrepancy shouldn't amount to too much of a difference, and it will oftentimes work in your favor if their number is greater than what you calculated for your own home. If you want to calculate the square footage of a house by this standard, as a general rule, add six inches per measurement, to make up the difference.

Take the final number with a grain of salt and don’t be afraid of checking it for yourself. It’s a task anyone with a measuring tape can do.