How to measure a room
Measure wall to wall at floor level along the longest straight runs. For irregular rooms, split the floor into rectangles, triangles and circles, add each as its own area, and the calculator totals them and draws them to scale so you can check nothing is missing.
| Shape | Formula |
|---|---|
| Rectangle | length × width |
| Triangle | base × height ÷ 2 |
| Circle | π × (diameter ÷ 2)² |
Common room sizes
| Room | Size | Square feet |
|---|---|---|
| Small bedroom | 10 × 10 ft | 100 |
| Bedroom | 12 × 14 ft | 168 |
| Living room | 16 × 20 ft | 320 |
| One-car garage | 12 × 22 ft | 264 |
| Two-car garage | 24 × 24 ft | 576 |
Questions people ask
How do I calculate square footage?
Multiply length by width in feet. A room 12 ft by 14 ft is 168 sq ft. For an L-shaped room, split it into rectangles, work out each one and add them together.
Can I enter feet and inches?
Yes. Type measurements the way you'd write them, like 12' 6" or 12 6 or 12.5. A plain number is read as feet.
How much extra flooring should I buy?
Add about 10% for straight-laid flooring and 15% for diagonal or herringbone patterns, to cover cuts and mistakes.
How many square feet are in a square yard?
A square yard is 3 ft × 3 ft, or 9 sq ft. Carpet is often priced per square yard.