Square Footage Calculator

Calculate square footage for rooms, homes, and properties. Supports rectangular, circular, and irregular shapes with instant results.

How it works

Rectangle = length × width. Triangle = base × height ÷ 2. Circle = π × radius². Total = sum of sections. Square yards = sq ft ÷ 9.

Worked example

A 14 ft × 18 ft room is 252 sq ft, plus a 6 ft × 8 ft alcove (48 sq ft) makes 300 sq ft — about 33.3 square yards or 27.9 m².

Frequently asked questions

How do I measure an irregular room?

Split it into rectangles and triangles, calculate each separately and add them. This is more accurate than averaging the longest and shortest walls.

How much waste should I add?

Add 10% for straight-lay flooring and paint, and 15% for diagonal or patterned layouts and tile — offcuts around doorways are rarely reusable.

How do I convert square feet to square metres?

Divide by 10.764. A 300 sq ft room is 27.9 m². Note that square units do not convert with the linear factor.