Calculate the area of any space in square feet or square metres. Choose your shape — rectangle, circle, triangle or trapezoid — enter the dimensions and get an instant result with automatic unit conversion between sq ft and m².
Enter dimensions to calculate area.
For irregular rooms, divide the space into sections (rectangles, triangles, etc.), calculate each area separately and add them together.
To convert a room measured in feet and inches, first convert to decimal feet (e.g., 12 ft 6 in = 12.5 ft) before multiplying length by width.
Measure the length and width of the room in feet (include any alcoves or closets within the space). Multiply length × width for the area in square feet. For L-shaped rooms, split into two rectangles, calculate each and add together.
Measure each room and add the areas together. Add 10% for straight lay, 15% for diagonal. Round up to the nearest full box or roll when ordering — most flooring is sold in fixed pack sizes.
A 10×10 room is exactly 100 square feet. This is a common reference point — a 10×10 room requires approximately 1 gallon of paint per coat, around 110 sq ft of flooring with waste, and about 12 bundles of shingles if it were a roof section.