An online calculator to calculate the diagonal, perimeter and area of a square given its side x as shown below. The length L of the diagonal, perimeter P and area A are given in terms of x by the formulas:

length of diagonal: L = √ (x^{ 2} + x^{ 2}) = x √2

Perimeter: P = 4 × x

Area: A = x^{2}

The above formulas may also be used to calculate any three of the above quantities given the fourth one as is shown below.

Calculate the Diagonal, Perimeter and Area Given the Side

Enter the side x and press "calculate". The outputs are the length of the diagonal L, the perimeter P and the area A.

Calculate the Side, the Diagonal and Perimeter Given the Area

Given the area A of the square, its side x is given by

Side: x = √A

Then the diagonal and perimeter are given by the same formulas above.
Enter the area A and press "calculate". The outputs are the side x, length of the diagonal L and the perimeter P.

Calculate the Side, the Diagonal and Area Given the Perimeter P

Given the perimeter P of the square, its side x is given by

Side: x = P / 4

Then the diagonal and area are given by the same formulas above.
Enter the perimeter P and press "calculate". The outputs are the side x, length of the diagonal L and the area A.

Calculate the Side, the Perimeter and Area Given the Length L of the Diagonal

Given the length L of the diagonal of the square, its side x is given by

Side: x = L / √2

Then the area and perimeter are given by the same formulas above.
Enter the length L of the diagonal and press "calculate". The outputs are the side x, the perimeter P and the area A.