Square footage calculator
Work out the area of any room, yard or odd-shaped space in square feet, by adding up rectangles, triangles and circles.
Split an odd-shaped space into simple shapes. Leave unused rows blank.
Total area
How to use it
Pick a shape and enter its measurements in feet. For an L-shaped room, a yard with a curved bed, or anything irregular, split it into simple shapes, enter each one on its own row, and the calculator adds them up. You also get the total in square yards, square meters and acres.
The formulas
| Shape | Area |
|---|---|
| Rectangle or square | length × width |
| Triangle | base × height ÷ 2 |
| Circle | 3.1416 × (diameter ÷ 2)² |
The height of a triangle is measured straight out from the base at a right angle, not along a sloping side.
| Unit | Equals |
|---|---|
| 1 square yard | 9 square feet |
| 1 square meter | 10.764 square feet |
| 1 acre | 43,560 square feet |
Measuring tips
- Measure to the nearest inch, then convert. 10 ft 6 in is 10.5 ft; 10 ft 3 in is 10.25 ft.
- L-shaped rooms: split them into two rectangles that don't overlap, and add the areas.
- Bay windows and angled corners: treat them as a rectangle plus a triangle.
- Curved garden beds: a half circle is a circle's area divided by 2. Enter the full circle, then halve the result.
Once you have the area, use it in the flooring, mulch or paint calculators.