The square footage formula
Area = length × width, with both measured in feet. When a side has inches, divide them by 12 first: 6 inches is 0.5 ft, 9 inches is 0.75 ft, and 3 inches is 0.25 ft.
| Inches | Feet | Inches | Feet |
|---|---|---|---|
| 1" | 0.083 ft | 7" | 0.583 ft |
| 2" | 0.167 ft | 8" | 0.667 ft |
| 3" | 0.25 ft | 9" | 0.75 ft |
| 4" | 0.333 ft | 10" | 0.833 ft |
| 5" | 0.417 ft | 11" | 0.917 ft |
| 6" | 0.5 ft | 12" | 1 ft |
Measuring irregular rooms
- L-shapes: divide into two rectangles and add them.
- Closets and alcoves: add each as its own area.
- Islands or built-ins: for flooring under cabinets you are not covering, measure them as an area and subtract the result.
- Triangles: multiply the two short sides of a right triangle and halve the result.
Square feet, yards and meters
| Unit | Equals |
|---|---|
| 1 square foot | 144 square inches · 0.0929 m² |
| 1 square yard | 9 square feet · 0.8361 m² |
| 1 square meter | 10.764 square feet |
| 1 acre | 43,560 square feet |
Need to add up the lengths first? Use the feet and inches calculator, then bring the totals here.
Square footage questions
How do I calculate square feet from feet and inches?
Convert each side to decimal feet by dividing the inches by 12, then multiply. A room 12' 6" by 10' 9" is 12.5 ft × 10.75 ft = 134.38 sq ft.
How do I measure an L-shaped room?
Split it into two rectangles, measure each, and add them. Use "Add another area" for each rectangle and the calculator totals them.
How much extra flooring should I buy?
Around 10% is a common allowance for cuts and waste with straightforward layouts. Diagonal or herringbone patterns often need 15% or more. Check the manufacturer's guidance for your product.
How many square feet are in a square yard?
There are 9 square feet in a square yard (3 ft × 3 ft). Carpet is often priced per square yard.