Need to figure out how much flooring, paint, or tile you need? Just enter your room dimensions in feet and inches, and our free square footage calculator does the math for you. It handles rectangles, L-shapes, and irregular spaces so you always get the right number. Perfect for home projects, renovations, and real estate.
Modify the values and click the calculate button to use
Square footage is just a fancy way of saying "how much floor space something takes up." Think of it like this: imagine you have a bunch of 1-foot by 1-foot tiles. Square footage tells you how many of those tiles you'd need to cover the entire floor.
It's written as "sq ft" or "ftยฒ." And it's used for everything from buying carpet to pricing houses.
Square footage is the total area of a space measured in square feet โ just multiply the length by the width and you've got it. Think of it as counting how many 1-foot tiles would cover your floor from wall to wall.
Here's the basic formula:
Length ร Width = Square Footage
That's it. If your room is 10 feet long and 12 feet wide, you've got 120 square feet. 10 ร 12 = 120. Done. But wait โ what if your room isn't a perfect rectangle? What if there's a bump-out or a weird corner? We'll get to that. First, let's make sure you're measuring correctly.
You don't need anything fancy. A tape measure works fine. A laser measurer is faster but not necessary. Just make sure whatever you use measures in feet. If it only shows inches, you'll need to convert (more on that in a sec).
For a rectangular room, measure the longest wall (that's your length) and the shortest wall (that's your width). Measure from wall to wall, not from baseboard to baseboard. And don't include doorways or openings โ those are just empty space. Pro tip: measure at the floor level, not at eye level. Walls aren't always perfectly straight, and the floor gives you the most accurate measurement.
This is where most people mess up. Your tape measure probably shows feet and inches. Like 12 feet 6 inches. You can't just multiply 12 ร 6. You need to convert those inches to a decimal. Divide the inches by 12. So 6 inches becomes 0.5 feet. Now your measurement is 12.5 feet. Our calculator handles this automatically โ just plug in your feet and inches, and it does the conversion for you.
Length ร Width. That's your square footage. If you measured in inches first, divide the final number by 144 (because there are 144 square inches in a square foot).
Not every room is a perfect rectangle. Here's how to handle the most common shapes.
Break it into two rectangles. Measure each rectangle separately, calculate their square footage, then add them together. That's it. For example: your L-shaped living room has a 10ร12 section and a 8ร6 section. That's 120 + 48 = 168 square feet total.
For a circle, you need the radius (that's half the width of the circle). The formula is ฯrยฒ. Pi (ฯ) is about 3.14. So multiply 3.14 by the radius squared. Example: a circular rug with a 5-foot radius. 3.14 ร 5 ร 5 = 78.5 square feet.
For a triangle, multiply the base (bottom) by the height, then divide by 2. So a triangle with a 10-foot base and 8-foot height is 10 ร 8 / 2 = 40 square feet.
Measure the main rectangle first. Then measure the alcove or bay window separately. Add them together. Don't try to measure around the bump-out โ it'll just confuse you.
Your bedroom is 12 feet by 14 feet. That's 168 square feet. But carpet usually comes in 12-foot wide rolls. So you might need to buy a 12ร14 piece (168 sq ft) or a 15ร14 piece (210 sq ft) depending on the roll width. Always check with the store.
For paint, you need wall square footage, not floor. Measure the height of each wall and the width. Multiply height ร width for each wall. Add them up. Then subtract windows and doors (a standard door is about 20 sq ft, a window is about 15 sq ft). Example: four walls, each 8 feet high. Two walls are 12 feet wide, two are 10 feet wide. That's (8ร12)ร2 + (8ร10)ร2 = 192 + 160 = 352 sq ft. Subtract one door (20 sq ft) and two windows (30 sq ft). You need paint for 302 square feet.
Tile is sold by the square foot, but you should buy 10% extra for cuts and breakage. So if your bathroom floor is 60 square feet, buy 66 square feet of tile.
Mistake #1: Measuring from the Wrong Spot
Don't measure from the baseboard or trim. Measure from the wall itself. Baseboards can add an inch or two, which throws off your numbers.
Mistake #2: Forgetting to Convert Inches
We mentioned this earlier, but it's worth repeating. 12 feet 6 inches is NOT 12.6 feet. It's 12.5 feet. Divide inches by 12 to get the decimal.
Mistake #3: Not Measuring Twice
Measure each wall at least twice. If the numbers don't match, measure a third time. Walls aren't always perfectly straight, so take the average.
Mistake #4: Including Closets in Room Square Footage
If you're measuring for flooring, include closets. If you're measuring for paint, don't include closet walls (unless you're painting inside the closet). Know what you're measuring for.
Mistake #5: Trusting Real Estate Listings
Real estate square footage often includes garages, basements, and other spaces. It might not match your actual living space measurement. Always measure yourself if accuracy matters.
Here's a fun way to think about it. Imagine you're laying down 1-foot square tiles. The length tells you how many tiles fit in a row. The width tells you how many rows you need. Multiply them, and you get the total number of tiles. That's square footage.
It works because you're essentially counting how many unit squares fit inside a shape. For rectangles, it's just rows times columns. For other shapes, you're breaking them into rectangles and adding them up.
Square footage has been around for centuries. The ancient Egyptians used a similar system to measure farmland along the Nile. They'd flood the fields, then measure how much land was covered. That's basically square footage โ measuring how much space something covers.
In the US, we use square feet because of the imperial system. Most other countries use square meters. One square meter is about 10.76 square feet. So if you see a European apartment listed as 50 square meters, that's about 538 square feet.
Use your phone: iPhone's Measure app and Android's Measure app can estimate distances. They're not as accurate as a tape measure, but they're great for quick estimates.
Measure around furniture: If you're measuring a room with furniture, measure the walls at the baseboard level. Slide the tape measure under furniture if you can. If not, measure from the opposite wall and subtract the furniture width.
Always round up: If your calculation gives you 167.3 square feet, round to 168. That extra foot might save you from running short on materials.
Our Square Footage Calculator is perfect for:
Measuring rooms for flooring, paint, or wallpaper
Calculating yard size for landscaping or sod
Estimating house square footage for listings or renovations
Figuring out tile or carpet needs
Any time you need quick, accurate square footage
Just enter your measurements in feet and inches, and the calculator does the rest. No math required.
If your measurements seem off, here's what to check:
Did you measure in the same units? Don't mix feet and inches.
Did you include all sections of an irregular room?
Are your walls actually straight? Old houses can have wonky walls.
Did you measure from the wall or the baseboard?
If you're still stuck, measure the room's perimeter (all walls added up) and compare it to your square footage. A 10ร10 room has a perimeter of 40 feet and 100 square feet. If your numbers don't match that ratio, something's off.
Break it into smaller rectangles. Measure each rectangle separately, calculate their square footage, then add them together. For L-shaped rooms, this works perfectly. For circles or triangles, use the specific formulas we covered above.
Yes. For paint, you only need the wall area. A standard door is about 20 square feet. A standard window is about 15 square feet. Subtract these from your total wall square footage to know how much paint to buy.
Square footage is used in the US and a few other countries. Square meters are used everywhere else. One square meter equals about 10.76 square feet. So a 100 square meter apartment is about 1,076 square feet.
Divide the inches by 12. So 6 inches becomes 0.5 feet, 9 inches becomes 0.75 feet, and 3 inches becomes 0.25 feet. Then multiply your length and width in feet to get square footage.
Real estate listings often include garages, basements, and other spaces that aren't part of the main living area. They might also use different measurement standards. Always measure yourself if you need accurate numbers for renovations or furniture.
Measure the room's length and width in feet. Multiply them. But remember that carpet comes in specific roll widths (usually 12 feet). You might need to buy more than the room's square footage to match the roll width. Always check with the store.
Multiply the base (bottom) by the height, then divide by 2. So a triangle with a 10-foot base and 8-foot height is 10 ร 8 / 2 = 40 square feet. This works for any triangle shape.
Measure the floor area the same way. But buy 10% extra tile for cuts and breakage. So if your floor is 60 square feet, buy 66 square feet of tile. This ensures you have enough for tricky cuts around corners and edges.
Yes. iPhone's Measure app and Android's Measure app can estimate distances. They're not as accurate as a tape measure, but they're great for quick estimates. For precise measurements, especially for buying materials, use a tape measure.
Forgetting to convert inches to feet correctly. 12 feet 6 inches is 12.5 feet, not 12.6 feet. Also, measuring from the baseboard instead of the wall, and not measuring twice to check for accuracy.
Measure the length and width of your yard in feet. For irregular shaped yards, break it into smaller sections, calculate each separately, and add them together. Always add 5-10% extra for waste when ordering sod or landscaping materials.
Multiply the length in inches by the width in inches, then divide by 144 (since there are 144 square inches in a square foot). For example, a 120-inch by 96-inch room = 11,520 sq inches รท 144 = 80 square feet.
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