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Square Footage Calculator
Square footage is the number every other remodeling estimate starts from. Measure your space below — pick its shape, enter the dimensions in feet, and get the area in square feet, square yards, square inches and square meters. Odd-shaped room? Calculate each section and use the project total to add them up.
Your results
Project total
Measuring a room in sections? Add each section's area here — the running total is what you feed into the paint, flooring and tile calculators.
Total so far: 0 sq ft
How it works
Every shape here is one of the standard area formulas, measured in feet so the answer comes out in square feet:
Circle: π × (diameter ÷ 2)²
Triangle: base × height ÷ 2
Trapezoid: (side A + side B) ÷ 2 × height
An L-shaped room is not a new formula — it is two rectangles. Split the room at the inside corner, calculate each rectangle, and add them. That is exactly what the project total above does, and it works for any room you can break into rectangles, which is nearly all of them.
Feet to square feet: the conversion that isn't one
People search "ft to sq ft" hoping for a conversion factor, but there isn't one: feet measure length, square feet measure area. A length becomes an area only when multiplied by a second length. 12 feet of 3-foot-wide flooring roll covers 12 × 3 = 36 sq ft. If a product spec gives you a length and a width, multiply them here and you have your square footage.
Measuring tips
Measure wall to wall at the floor, in two places — rooms are rarely perfectly square, so use the longer pair of measurements for material estimates. Round each dimension up to the nearest inch (0.1 ft) rather than down; every calculator on this site adds waste on top, but an under-measured room defeats the waste factor. Skip closets and alcoves into their own section instead of stretching the main rectangle.
Worked example
A bedroom 12 ft by 10 ft: 12 × 10 = 120.00 sq ft — which is 13.33 sq yd, 17,280 sq in, or 11.15 m². A round patio 10 ft across: π × 5² = 78.54 sq ft. An L-shaped living room made of a 12×10 section plus a 6×4 nook: 120 + 24 = 144 sq ft. Try all three with the shape selector above.
Frequently asked questions
How do I calculate the square footage of a room?
Measure the length and width of the room in feet and multiply them: length × width = square feet. For a room that isn't a plain rectangle, split it into rectangles (and the odd triangle), calculate each piece, and add the areas together — the project total above does the adding for you.
How many square feet is a 12x12 room?
144 square feet. 12 ft × 12 ft = 144 sq ft. It is one of the most common room sizes in US homes, which is why flooring and carpet are often priced with it as the example.
How do I convert square feet to square yards?
Divide by 9. One square yard is 3 ft × 3 ft = 9 sq ft. Carpet and sod are usually sold by the square yard or priced from it, so a 120 sq ft room is 13.33 sq yd.
Can I convert linear feet to square feet?
Not directly — you need a width. Linear feet measure a line; square feet measure a surface. Multiply the linear footage by the width of the material in feet. Ten linear feet of 2-ft-wide countertop is 20 sq ft; the same 10 ft at 1 ft wide is 10 sq ft.
Should I subtract closets, stairs or fixtures from the area?
For flooring and paint, subtract nothing for small fixtures — the waste factor absorbs them, and the material under a toilet flange or inside a closet still has to be bought and cut. Do measure a large closet or alcove as its own section and add it, rather than pretending the room is one big rectangle.
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CalculatorTile Calculator
Tiles and boxes for floors and walls from your area and tile size, waste included.
About the author
Harrison Alley is a web publisher and data enthusiast based in Dallas, Texas. He built Urbarama’s remodeling calculators and maintains them.
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