Square Calculator
Calculate a square's area, perimeter and diagonal from its side length, in the unit of your choice.
About the Square Calculator
A square is a special rectangle with four equal sides and four right angles. Its area, perimeter and diagonal are all determined by a single side length. The side length has its own unit selector, and so does every result — pick inches for your input and square meters for your area if that's what you need, and the calculator converts everything automatically.
Formulas: Area = s² · Perimeter = 4s · Diagonal = s√2
Because every side is the same length, a square's measurements simplify nicely compared to a general rectangle: the perimeter is just four times the side, and the diagonal follows directly from the Pythagorean theorem applied to two equal legs.
Squares are everywhere in design and construction — floor tiles, picture frames, city blocks and chessboard squares are all typically built to this shape, which is why finding its area, perimeter and diagonal from a single measurement is so useful.