How Big Is a Square Foot, Really?

how big is a square foot

Sweeping your problems under the carpet? Perplexed by your floors? “Expert” Alex Plainett gives advice on everything from grout griping to tile tantrums. In this edition, Alex answers the age-old question: How big is a square foot?

Dear Alex Plainett:

I’ve moved into my childhood home, which is fantastic, except that when my parents moved to retire in California, their poodles left the living room carpet in a mess. I obviously want to get new carpet, but I keep reading that I have to find the square footage of the room to know how much carpet to buy. My geometry notebooks might still be in the attic—but, Alex, can you just tell me how big is a square foot, and what it is in plain English?

Square Footage Is for Squares

Dear Square:

Thanks for writing! No matter how long ago you learned geometry (or even if you never did), it’s still handy to be able to figure out square footage. You’ll need that knowledge for lots of things, like buying new flooring, selling your house, and choosing an apartment.

When it comes to buying carpet, the point of knowing how big a square foot is, is to be able to measure how much carpet you need—which can help avoid carpet seams.

The good news? You can use a square-foot calculator online.

how big is a square foot calculator

But it’s not that intimidating to figure out what a square foot is. There’s a simple formula you can use, even if you’re no math wiz:

length x width = square footage

If that still looks like another language to you, here’s how you can do it yourself:

  • Get a measuring tape and measure the width of the room from wall to wall at the widest part. Write that number down.
  • Now measure the length from the longest part, wall to wall. Write it down.
  • Multiply the two numbers together, and there’s your square footage!

But here’s the tricky part. If the room is an odd shape, you can divide it into squares or rectangles, and measure the length and width of those individually, multiplying the length and width of each of them just like you would a whole room. Then, add up the results. It’s sort of like creating a bunch of mini rooms to equal your whole room.

So, let’s say you divided the odd-shaped room into four “mini rooms,” and they measured 150 square feet, 100 square feet, 50 square feet, and 25 square feet. In the end, you’d add those together to see that your room is 325 square feet.

And, here’s a pro tip: Get more carpet than you measured (especially if it’s patterned carpet), just in case your calculations were off. If you end up with leftover carpet, you can use it to kneel on when gardening, inside a closet, or under heavy furniture for moving—there are actually a ton of uses for old carpet. The point is: Better to be safe than sorry.

Alex Plainett

Need flooring that measures up? Find a STAINMASTER® retailer near you.

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