How to Calculate Square Footage

For a simple rectangular room: length × width. For a triangular section: base × height ÷ 2. For a circular area like a round patio: π × radius².

Irregular rooms are just combinations of these shapes. Break the space into rectangles, triangles, and circles you can measure individually, calculate each one, and add them together — this is exactly what the multi-area Square Footage Calculator does for you.

Always measure at the longest point of each wall, not along baseboards or trim, which can shave inches off your total.