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Square Footage Calculator

A square footage calculator finds the area of a space — and converts it for you. Pick the shape (rectangle, L-shape, triangle or circle), enter the measurements, and it returns the area in square feet, square metres, square yards and acres at once.

Your measurements

Result

It's the starting point for almost every other estimate on the site: flooring, paint, tile and turf all begin with the area. Get this number right and the rest follows.

How it is calculated

Rectangle = length × width; L-shape = the overall rectangle minus the notch; triangle = half of base × height; circle = π × radius². We compute in a common unit, then convert: 1 sq ft = 0.0929 m², a square yard is 9 sq ft, and an acre is 43,560 sq ft.

Steps

Choose the shape that matches your space.
Enter the measurements in feet (or switch to metres).
For an L-shaped room, enter the overall size and the notch to subtract.
Read the area in square feet — plus metres, yards and acres.
Carry that number into the flooring, paint or tile calculators.

Worked example

A 12 × 10 ft room is 120 sq ft (about 11.1 m², 13.3 sq yd, 0.003 acres).

Common questions

How do I calculate square footage?

Multiply length by width for a rectangle. For other shapes pick it from the menu — the calculator handles triangles, circles and L-shapes.

How many square feet in a square yard?

Nine. Carpet and concrete are often sold by the square yard, so divide your square footage by 9.

How do I measure an irregular room?

Split it into rectangles, work out each one, and add them — or use the L-shape option to subtract a notch.

How many square feet in an acre?

43,560. The calculator shows acres automatically, which is handy for land and large lots.