About the square calculator
A square has four equal sides and four right angles, so a single measurement fixes everything else. Enter the side, the diagonal, the perimeter or the area and the calculator derives the other three.
The diagonal of a square is always √2 ≈ 1.41421 times the side, which follows directly from the Pythagorean theorem: d² = a² + a².
Formulas
| Area | A = a² |
| Perimeter | P = 4a |
| Diagonal | d = a√2 |
| Side from area | a = √A |
Frequently asked questions
How do I find the side of a square from its area?
Take the square root of the area: a = √A. A square with area 50 cm² has sides of √50 ≈ 7.0711 cm.
How do I find the area of a square from its diagonal?
A = d²/2. Because d = a√2, squaring gives d² = 2a², so the area a² is half the square of the diagonal.