Home › Square Footage Calculator
Square Footage Calculator
Calculate the area of a room, patio, lawn or plot. Choose a shape, enter the dimensions, and get square feet, square yards, square meters and acres.
Results are estimates. Soil, stone and mulch settle, weigh differently and vary by supplier. Confirm quantities and local requirements before ordering.
How to calculate it
Rectangle: length × width. Circle: π × radius². Triangle: base × height ÷ 2. Trapezoid: (side A + side B) ÷ 2 × the distance between them.
For L-shaped or irregular spaces, split them into simple shapes, calculate each one, and add the results. To subtract a cut-out such as a pool or building, calculate it separately and subtract.
Worked example
A 20 ft × 12 ft room:
| Square feet | 240 sq ft |
|---|---|
| Square yards | 26.67 sq yd |
| Square meters | 22.3 m² |
| Square inches | 34,560 sq in |
| Acres | 0.00551 |
Area conversions
| From | To |
|---|---|
| 1 square yard | 9 square feet |
| 1 square meter | 10.764 square feet |
| 1 acre | 43,560 square feet |
| 1 square foot | 144 square inches |
Tips
- Measure twice at the widest points and use the longest straight lengths for rectangles.
- For flooring, tile and sod, add 5–15% for waste on top of the exact area.
- Square footage of a home is usually measured on finished interior living area. Garages and unfinished areas are often excluded.
Frequently asked questions
How do I calculate square footage?
Multiply length by width in feet for a rectangle. For other shapes use the matching formula and add the areas together.
How many square feet is 12 × 12?
144 square feet.
How many square feet are in an acre?
43,560 square feet.
How do I convert square meters to square feet?
Multiply square meters by 10.764. Or pick meters in the unit dropdown and the calculator does it for you.