How to Figure Your Finished Square Footage

There seem to be a lot of discrepancies on the finished square footage of homes here in Tulsa. Most Real Estate contracts require a disclaimer statement be included since often municipal records don’t match appraisal figures and vice versa.

My first job in real estate license was working for an appraisal firm. Since all appraisals require a review of finished square footage, my manager taught me a simple way to calculate this. As a homeowner or future homeowner, you should know the finished square footage of a house, as it is the most significant factor in calculating it’s value. You will need a pencil, legal pad, 100 foot open reel measuring tape, and a calculator.

First step is to make a rough drawing of your home’s floor plan on a sheet of paper. The dimensions of the interior rooms need not be precise, but be sure you have a good outline of the exterior walls. Most houses are simple rectangular boxes stuck together. A single floor ranch, bungalow, or cabin will be the easiest to measure. If your home has a second floor, draw the second story floor plan separately next to your first floor. More on second floors in a minute.

Second step is to go outside with your tape and measure the width and length of your homes exterior walls. Remember, you are measuring finished square footage, so your garage patio or porch will not count in FinSqFt. Always look at your drawing to guide you.

Again, if your house is a ranch or bungalow, you should have two measurements — width and length. If your house has potions that jut in and out, measure each flat surface from corner to end. Place these measurements on your drawing so you can clearly see the exterior dimensions.

To calculate square footage, simply multiply length by width. Subtract 1 foot from both dimensions to allow for the exterior wall’s thickness. If your house has a wing or addition, you should see this as a second box protruding from the main structure. Usually you can see an outside dimension that defines the extra length or width beyond the main structure. You can draw a line to cut this box off and define it’s dimension separately, then add the two together.

Now back to the second story. If your house is a colonial, that’s simply two identical sized boxes, one on top of the other. For this style you can just used the downstairs area and double it. But many homes have partial second floors which are built into the roof of the house with knee walls located inside the home’s exterior dimension. In this case, best to measure inside dimensions to calculate second floor finished square footage.

Use your tape to measure the total width and length of the finished area. Finished square footage is any part of your home that is heated. Most closets are part of your finished square footage, but a utility area where the air-handler is located is probably not.

You may have a few more dimensions than you did on the first floor, but use your drawing to guide you. You may have to open doors to run your tape from one side of the upstairs to the other. Remember, look for the boxes. If rooms jut out , measure the extra length or width and include that on your drawing. Measure dead space like stairwells or vaulted foyers and subtract these areas from the larger dimensions.

This is just a brief lesson in figuring the finished square footage of your home. Remember, draw first, then measure. If you even the faintest memory of high school geometry, you’ll be fine. Use your findings to check that tax records and appraisals are within range of your home’s square footage.