Measure any rectangle, circle or triangle to get the area in square feet — plus square yards, square meters and acres.
The method behind this calculator
This square footage calculator finds the area of the three most common shapes and converts it into every unit you might need. It’s perfect for flooring, sod, tiling, painting and pricing anything sold per square foot.
Add a price per square foot to estimate the material cost, and combine multiple identical areas with the count field.
Getting your answer
- Pick rectangle, circle or triangle and enter the dimensions.
- Set how many identical areas you have.
- Read the square feet and other units, and add a per-ft² price for cost.
The calculation
rectangle = length × width
circle = π × (diameter ÷ 2)²
triangle = ½ × base × height
Try it with these numbers
The calculator opens with a length of 12, width of 10, diameter of 10. On those figures the total area is 120. Underneath, Square feet comes out at 120 and Square yards at 13.33. Change any field and every figure updates as you type.
Common questions
How do I calculate square footage?
For a rectangle, multiply length by width in feet. For a circle use πr², and for a triangle use half the base times the height.
How many square feet in a square yard?
Nine — a square yard is 3×3 feet.
How do I find square footage of an odd room?
Split it into rectangles and triangles, calculate each, and add them together using the count or by adding the results.