Square Footage Made Simple: What Every Homeowner Should Know

A Homeowner’s Guide to Understanding Livable Space

When it comes to buying or selling a home, square footage is one of the most important — and misunderstood — numbers. That seemingly simple figure can influence everything from home value to mortgage approval. But here’s the catch: there’s no universal method for measuring it.

That doesn’t mean you’re stuck guessing. With the right approach, measuring a home’s square footage is straightforward — and we’ll walk you through it step by step.

What Is Square Footage, Really?

When people talk about the “size” of a home, they’re usually referring to the Gross Living Area (GLA) — the total amount of finished, accessible living space in a home.

But not everything under the roof counts toward that number. Spaces like garages, unfinished basements, or screened-in porches often don’t make the cut. Understanding what should (and shouldn’t) be included is key to an accurate measurement.

How to Measure Square Footage Like a Pro

Here’s a simple process to help you calculate square footage — no advanced math degree required.

1. Sketch a Floor Plan

Draw each floor of the home separately. Be sure to exclude unfinished spaces, exterior features, and garages. Focus on the actual living areas.

2. Divide Into Rectangles

Break the home into rectangular sections — even oddly shaped spaces. This makes it easier to calculate individual areas.

3. Measure Each Rectangle

Use a tape measure to find the length and width of each space. Round to the nearest half-foot. (For example, 13.3 feet becomes 13.5 feet.)

4. Calculate the Area

Multiply each rectangle’s length by its width to find the square footage. Write this total down in your sketch.

5. Add Everything Up

Sum the square footage of all rectangles for each floor, then combine the floors. Round your final number to the nearest square foot.

What to Include (and Exclude)

It’s easy to get tripped up by what counts. Here’s a quick guide:

Include in Square Footage:

Finished areas with 7-foot minimum ceiling height
Finished attic spaces that meet clearance rules
All livable stories (first floor, second floor, etc.)

Do Not Include:

Garages
Unfinished basements (even if they're partially used)
Outdoor areas (patios, porches, staircases)

Even though you may not include a finished basement in your home’s official square footage, it’s still smart to measure it for your own records — and it can still add value in other ways.

Why Square Footage Matters (a Lot)

Whether you’re buying or selling, an accurate measurement ensures:

Fair pricing
Honest listings
Fewer surprises during appraisals

For instance, a seller might list their home as 2,000 square feet based on a builder’s plans — but if an appraiser comes back with 1,600 square feet of verified GLA, it could result in a price drop or derail the sale entirely.

As a homebuyer, it’s just as important to ask questions and verify the square footage with a trusted real estate professional or appraiser. It’s your investment — make sure you’re getting what you pay for.

Final Thoughts

Square footage might seem like a technicality, but it’s a critical piece of your homeownership puzzle. Taking the time to measure it correctly — or verify someone else’s numbers — can give you the confidence to move forward in your home journey.

And when you’re ready to make that next move? Our BankFirst Mortgage Team is here to help you every step of the way.

* Specific loan program availability and requirements may vary. Please get in touch with your mortgage advisor for more information.