How to calculate the square footage of a room

Measure rectangles, L-shaped rooms, triangles, and circles — then add the right extra for flooring, tile, or paint.

Square footage is the area of a floor, wall, or plot, measured in square feet. You need it to price flooring, tile, carpet, and paint. Most rooms are simple shapes, and odd rooms are just a few simple shapes added together. Rectangles and squares Area = length × width. A bedroom that measures 12 ft by 14 ft is 168 square feet. Measure wall to wall at floor level and round to the nearest inch. Measuring tips Measurements in feet and inches Turn the inches into part of a foot before you multiply: divide the inches by 12. A wall of 10 ft 6 in is 10.5 ft. A wall of 12 ft 9 in is 12.75 ft. L-shaped and irregular rooms Split the room into rectangles that do not overlap, work out each area, and add them up. An L-shaped living room might be a 16 × 12 ft rectangle (192 sq ft) plus an 8 × 6 ft nook (48 sq ft), for 240 square feet in total. Triangles and circles Square feet and square metres 1 square metre is about 10.764 square feet, and 1 square foot is about 0.0929 square metres. Convert once at the end, after adding up all the areas, to avoid rounding errors. Add extra before you buy Cuts, mistakes, and pattern matching use extra material. Common allowances are about 5–10% for flooring la…