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PaydayNow Explains How to Calculate a Home’s Square Footage (and why it matters)

When you buy a new home, measuring its square footage is probably not top of mind. While it may appear trivial, it is one of the most crucial variables in determining a property’s worth.

“Mismeasure a quality and it cascades. “It will affect the entire value,” says Merjen Novosel, a financial expert at PaydayNow.

Why do square footage matters?

You may need to know how to determine a house’s square footage to sell it, contest a high tax assessment, or renovate to create extra space.

When planning to sell your home, the exact size of the property is an important aspect in deciding the asking price. “We’ll compare it to comparables,” adds Novosel, who looks for homes of similar size in the region. An incorrect square footage measurement may lead to an incorrect assessment price.

For the same reasons, square footage (commonly abbreviated as SF or SQFT) counts in mortgage-backed real estate. The lender will need it to verify the property’s value.

However, knowing your home’s square footage has significant benefits. For example, if you want to finish an unfinished basement or attic, you may need to give the square footage to get a building permit.

If your county or municipality levies greater taxes than you believe you should owe, checking the square footage can help you minimize your property taxes.

How to calculate a house’s sqft

Start with a few basic items to measure the square footage of a house, condo, or townhouse:

Calculator (pencil)

Measuring tape or laser tool

If the property is a rectangle, multiply the length and width. For example, a 60 by 40 foot one-story house is 2,400 square feet (60 × 40 = 2,400).

Most properties have more complicated layouts. In this situation, simply follow these methods to calculate square footage.

Make a basic layout of your complete space, marking all necessary rooms. Hallways and vestibules are “rooms.”

Measure each room’s length and width in feet. Add the length and width together to get the room’s square footage. As in: A 12 x 20 bedroom is 240 square feet (12 x 20 = 240). Write the total square footage for each room on your sketch.

Add the measurements of each room to get your home’s total square footage.

Your floor plan may be available from your developer if you live in a tract house, condo, or townhome neighborhood. Your square footage may already be computed.

What to omit?

Exclude space you can’t walk on or live in while obtaining measurements. These areas are not considered “gross living areas.”

“If you have a two-story house, you multiply the first-floor measurement by two,” Novosel adds. However, a two-story entryway cannot be counted as a non-usable area.

Not all square footage includes completed basements and garages. Basements are often excluded due to their construction being below grade. If your state allows allowing basements, you’ll need an ingress and egress, or a safe route to enter and depart the basement to the outdoors.

Finished attics can contribute to the total square footage of your home if they meet certain criteria. If you intend to sell your home, work with a real estate agent to create an accurate listing.


If determining your property’s square footage seems daunting, try hiring a professional assessor. An average single-family house appraisal costs around $350. Condo appraisal fees range from $300 to $500, while multi-family home appraisal fees range from $600 to $1500.

While two expert appraisers may arrive at somewhat different square footage figures for the same home, they all strive for scientific accuracy. “We always aim for a 1 to 3% variance,” Novosel explains.