How to use it
Enter the length and width of each rectangle; the small box next to feet takes extra inches, so 12 ft 6 in is 12 and 6. For an L-shaped room, split it into two rectangles and add the second with Add another area. Triangles and circles work the same way.
The formulas
Rectangle: length × width Triangle: base × height ÷ 2 Circle: 3.1416 × (diameter ÷ 2)² 1 sq yd = 9 sq ft · 1 m² = 10.764 sq ft · 1 acre = 43,560 sq ft
Example: a 12 × 15 ft bedroom is 12 × 15 = 180 square feet, which is 20 square yards or 16.7 m².
Common room sizes
| Room | Square feet | Square yards |
|---|---|---|
| 10 × 10 ft | 100 | 11.11 |
| 10 × 12 ft | 120 | 13.33 |
| 12 × 12 ft | 144 | 16 |
| 12 × 15 ft | 180 | 20 |
| 14 × 16 ft | 224 | 24.89 |
| 20 × 20 ft | 400 | 44.44 |
Measuring tips
- Measure wall to wall at floor level, to the nearest inch.
- For flooring, buy 5 to 10 percent more than the area for cuts and mistakes. The tile calculator counts tiles exactly.
Questions
How do I calculate the square footage of a room?
Multiply the length by the width, both in feet. A 10 × 12 ft room is 120 square feet.
How do I measure an L-shaped room?
Split it into two rectangles, work out each area and add them. Use Add another area for the second part.
How do I convert square feet to square yards?
Divide by 9. 180 square feet is 20 square yards.
How many square feet are in an acre?
43,560 square feet.