Home Improvement
Square Footage Calculator
The square footage calculator finds the area of a room, lot or surface for a rectangle, triangle, circle or trapezoid. Enter measurements in feet, inches, yards or metres and get the area in square feet, square yards, square metres and acres, plus a cost at your price per square foot.
Area formulas
| Shape | Formula |
|---|---|
| Rectangle | length × width |
| Triangle | ½ × base × height |
| Circle | π × radius² |
| Trapezoid | ½ × (side A + side B) × height |
For a room with an odd outline, split it into rectangles, calculate each one and add them up. Subtract areas you do not need, such as a fireplace or a built-in.
Example. A 14 ft × 12 ft room is 168 ft², which is 18.67 yd² or 15.61 m². At $4.50 per square foot of flooring the material costs $756.
Square footage for flooring and paint is only the starting point. Order extra for waste, usually 5% to 15% depending on the pattern and layout.
Questions people ask
How do I convert square feet to square metres?
Multiply square feet by 0.0929. One square metre is about 10.764 square feet.
How many square feet in an acre?
There are 43,560 square feet in one acre.
What about inches?
Choose inches as the unit, and the calculator converts the result to square feet for you.