square footage calculator
Add up as many rooms or sections as you need, whether they’re rectangles, circles or triangles, to get total square footage, square metres and a cost estimate.
fashion law journal · tools deskupdated 25 sep 2026ft, in, m
Quick answer: square footage = length × width, in feet. A 12 × 15 ft room is 180 sq ft. For an L-shaped room, split it into two rectangles and add them. One square metre is 10.764 square feet.
area formulas
| shape | formula | example |
|---|---|---|
| Rectangle or square | length × width | 12 × 15 ft = 180 sq ft |
| Circle | π × radius² | 10 ft across = 78.5 sq ft |
| Triangle | base × height ÷ 2 | 10 × 8 ft = 40 sq ft |
| L-shape | split into two rectangles | 180 + 60 = 240 sq ft |
add waste before you order
Flooring, tile and turf are sold by area, but you’ll lose some to cuts. Add about 5 to 10% for straight layouts and 15% for diagonal or herringbone patterns. Round up to whole boxes or rolls.
Listing a home? In the US there’s no single national rule for “square footage” in listings. Most appraisers follow the ANSI Z765 standard, which only counts finished, above-grade space. Your measurement may differ from the listing’s.
square footage questions
How do I calculate square footage of a room?
Measure the length and width in feet and multiply them. If a measurement includes inches, divide the inches by 12 and add them to the feet (10 ft 6 in = 10.5 ft).
How do I convert square feet to square metres?
Divide by 10.764. So 200 sq ft is about 18.6 m².
How many square feet in a square yard?
Nine. Carpet is sometimes priced per square yard, so divide your square footage by 9.
What’s the square footage of an acre?
43,560 square feet.
Results are estimates for planning. Measure twice before ordering. More tools: cubic yard calculator · gravel calculator.