How to measure square footage in Utah

Square footage is simply area. A room that is 10 feet by 12 feet holds 120 square feet, because 10 times 12 is 120. A whole house is a set of rooms added together, one floor at a time.

For tools, a long tape or a laser measure works, along with graph paper and a pencil. A second person to hold the far end of the tape makes the job go faster.

1. 1Sketch each floor

   Draw every floor on graph paper, one box for each foot. Measure each floor on its own, since an upper floor is often smaller than the one below it.

2. 2Measure room by room

   Write down each room's length and width in feet, and include the halls and closets. Count the stairs on the floor they go down from.

3. 3Break odd shapes into rectangles

   An L-shaped room is two rectangles. Work out each one, then add them. For a triangle, take half of its base times its height.

4. 4Keep three totals

   Add the rooms above the ground into one total. Keep the basement as a second total and the garage as a third.

5. 5Round at the end

   Measure to the nearest inch as you go. Round only the final total, to the nearest whole square foot.

Take an L-shaped main floor. One part is 20 by 24 feet, which is 480 square feet. The other part is 14 by 12 feet, or 168. A bay window sticks out 2 feet along a 6 foot wall, so that triangle is half of 6 times 2, which is 6. Add the three, and the floor holds 654 square feet.

Expect your room by room total to come out a little smaller than an appraiser's. The appraiser goes around the outside of each floor's exterior walls, so the thickness of the walls is part of the number. A tape inside the rooms leaves the walls out. Neither number is wrong; they measure two different things.

Working in inches? One square foot is 12 inches by 12 inches, which is 144 square inches. Multiply the inches, then divide by 144 to get square feet. To picture a size, a 300 square foot room is 15 by 20 feet, or about 17 by 17.

Measuring for flooring or paint instead of a sale? Use the same steps, then buy a little extra to cover cuts and waste.

Since 2022, Fannie Mae, which buys home loans from lenders, has required appraisers on its loans to measure with a national standard called ANSI Z765. Under that standard, a level counts as a basement if any part of its walls sits below the ground. A finished basement is still a basement. So is a lower level with big windows that walks out to the back yard.

FHA and VA appraisals leave the basement out of living area as well. Whichever loan you use, expect the basement to show up apart from the rooms above it.

So an appraisal shows two numbers where a listing may show one. The living area above the ground is the first. The basement, with any finished rooms in it, sits on a separate line, and the appraiser adjusts the value for it there. Fannie Mae notes that finished rooms below the ground can add a good deal of value. A smaller living area number does not mean your basement counts for nothing.

Listings can tell the story another way. In November 2026 I read a listing from the Wasatch Front Regional MLS whose living area total took in an unfinished basement. Its price per square foot was worked out on that whole total. The same listing also broke the size out floor by floor, with an above-ground line and a basement line, and it said every measurement should be checked on your own.

Many Utah homes have a basement, so for any Utah home, check how the listing counts it and how the county record counts it. Then compare above-ground size with above-ground size, never one home's big total with another home's smaller one.

Fannie Mae says so in its own guidance: the square footage in local MLS systems and in county records may not follow its standard. The appraiser may not know how the listing or the county measured, and still has to measure your home by the standard. Fannie Mae adds that appraisal living area is often different from other sources, because of low ceilings, walls below the ground, or space cut off from the main living area.

• The listing

  Entered for the sale, and it can fold the basement into its total. Look for the above-ground line and the size of each floor.

• The county record

  A county assessor may use the national standard, another method or local practice. The record can also be years old.

• The builder's plan

  Plans are drawn before the house goes up, and the finished house can differ. The national home builders group backs the same standard appraisers use.

• The appraisal

  Measured around the outside walls, above the ground only, with the basement on a line of its own.

• Home search sites

  They copy the listing or the county record, so they carry the same gaps, and at times an older number.

No law makes a seller or an agent use the appraisers' standard. It is a voluntary standard that lenders require of appraisers. So when two numbers disagree, find out which method each one used before you decide that one of them is wrong.

To find the size your county has on record, use the county assessor's online parcel search. In Salt Lake County, you can search by address, and the parcel record shows the above-grade square feet and the basement area as two separate numbers. Utah County's land records can be searched by address as well. If your county's search is hard to find, call the assessor's office. If the county's record of your own home's size looks off, ask that office to take a look. My guide to Utah property taxes covers how a value appeal works.

Selling, and the appraisal came back with a smaller size than your listing? My seller guide to appraisal problems walks through your options.

Due diligence is your window to check out the home before you are locked in. Under Utah's state purchase contract, as of November 2026, it includes checking the square footage or acreage of the land and of the home itself. That work happens by your Due Diligence Deadline, a date set in your own contract. Send a written cancellation by that deadline, and your earnest money is returned to you.

The contract also says you take the home as it is and rely on your own checks. A home inspector looks at the condition of the house, not its size, so the report will not catch a wrong number. If size matters to your offer, measure the home yourself, or hire an appraiser or a measuring service to do it.

Checked November 2026. A new state form took effect November 1, 2026; the December 2024 form may still be used through December 31, 2026. The square footage line is in both.

The walls make the difference. In a building of stacked units, the appraiser measures your unit from the inside of its walls. A townhome or other attached home follows the same outside-wall rule as a detached house, and the basement rule applies the same way.

The standard also covers an accessory dwelling unit, a small second home on the same lot. It does not cover buildings with two to four units, or sheds and other outbuildings.

Fannie Mae itself has noted that phone apps can measure houses, draw floor plans and work out living area. They are quick and handy for a first look at a home. A small miss on each wall can add up across a whole house, though, so check two or three walls by hand before you lean on the total.

When the number will matter in a deal, a tape and a sketch are still your backup. For the number your lender uses, the appraiser does the measuring.