Square Calculator
Enter the side length of a square to get its area, perimeter and diagonal. You can also enter the area or diagonal to recover the side and other properties.
Enter a value
Enter a value and press Calculate.
Square formulas
Area: A = s²
Perimeter: P = 4s
Diagonal: d = s·√2
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Frequently asked questions
The diagonal is the distance from one corner to the opposite corner. It equals side × √2 — a consequence of the Pythagorean theorem applied to the two sides of the right triangle formed by a diagonal.