How to Measure the Square Footage of a House

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.


Using your measuring device, calculate the length and width of each room. The simple math of length times width gives you the square footage of each room. Take the alcove and closet measurements separately, and add those numbers to the square footage of the room.

Raleigh Realty Homes lays out the process for measuring the square footage of a room with closets and an alcove: If a bedroom measures 12 x 14, the square footage of the room is 168 (12 times 14). If the closet is 3 x 8, add another 24 square feet to the room. An alcove that’s 3 x 3 adds another 9 feet. The total square footage of the room is 201.


7. Get a Subdivision Plat Map

If your property falls under the neighborhood subdivision, you’re most likely able to get the precise area size of your lot from the neighborhood’s entire subdivision plot map. 

Also, if your property falls under a district under construction, you should be able to easily get the subdivision plat map from the company that sold your lot to you. 

In the case where the neighborhood isn’t under construction, there’s a possibility that you get a subdivision plat map from your local municipality. 

Benefits of Accurate Dimensions

Getting accurate dimensions go a long way in helpi

Getting accurate dimensions go a long way in helping anyone taking charge of your building project confirm that your building is best suited for the space you have and create 3D drawings to give you a mini model of your property. 

Furthermore, in going through the approval period of your purchase, accurate dimensions come in handy; you can indicate your acceptance or otherwise of the plans.

Having accurate dimensions helps in ensuring that you purchase the correct size when purchasing land. 

7 Easy Ways to Find Your Lot Size

Here are some easy places and methods you can use to determine your lot size, depending on the resources available to you.

Property Deed

This is probably the easiest way to determine the size of your lot. If you own your property, all you need to do is read your property deed. 

This document should have a description of your property boundary as well as the size of the lot.

Measure Map Application

This application allows people to precisely measure perimeters, distances, and areas.

It can be utilized for both small and large area measurements. You can also share the results using any sharing app on your device. 

The surface area of buildings, plots, floors, or forest areas can be determined in your absence. It also works for physical measurements. All this can be done from the comfort of your tablet or Smartphone.

Property Plat Map

If you are a property owner, you will have received a plat map at the property closing. This map shows a plan of your lot with some basic information. 

The plat map includes the lot layout, the boundary dimensions, and tax parcel identification number. The lot information should also include the area of your land plot.

This figure should be an accurate indicator of your lot size. As long as the plat map was designed by a professional surveyor, the information should be authentic.

Lot Area Calculator

These digital applications can be downloaded to smart phone devices.

They will give you information about the lot dimensions or the size measurements. You will also get the lot perimeter measurement.

Professional Survey Services

This method may be the most expensive option for determining your home lot size.

Hiring a professional survey service for your property is also the most accurate option for obtaining the lot size.

The property deed may already include an accurate size of your property. The preparation of a professional survey plan is needed if you do not believe that the property deed is correct.


Pacing is the least accurate method of determining a lot size. Pacing is quick and easy when trying to get a quick estimate and when accuracy is not required.

This method involves measuring the length of one of your steps. You then measure the number of steps it takes to cover the site length and the site width. 

After taking all the necessary measurements and doing some basic math, you can calculate the site area.

Measuring Wheel

A measuring wheel allows you to measure the distance on land through a wheel. To use this device, you roll it over the area you wish to measure and record the results.

With this method, you may have to buy a measuring wheel. But your measurements are more accurate than the results you’ll get from pacing.

Just like pacing, some basic math is involved. You have to calculate the area of your lot after the measurements have been taken.

Measure the elevation of a point

  1. On the map, place your cursor to the point that you want to measure the elevation.
  2. At the bottom right, you can find the elevation at the rightmost part.

Tip: You can’t measure the elevation difference between two points.

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.

Discrepancies in measurement

Because square footage is so vital in appraising a home, it’s important to pay close attention to what is being measured.

Some sellers may include an unfinished basement in their square footage, giving you an inaccurate picture of the livable portion of the home.

And architects and appraisers often calculate square footage by using exterior walls, which may conflict with a property’s GLA figure.

Regardless of how you measure your square footage, be transparent when selling, and diligent when buying.

If you claim that your home is 2,000 square feet based on your builder’s floor plans, and a buyer’s appraiser brings back a figure of 1,600, you could lose the sale or need to lower your price.

Similarly, as a buyer, make sure to do your research and get an independent square footage to ensure you’re getting what you pay for.

Find and claim your home on Zillow to see its recorded square footage and to make edits as needed.


Originally published June 23, 2015.


Leave a Comment