Area of Square Calculator
Area
—
Perimeter
—
Diagonal
—
How to Calculate the Area of a Square
A square is a special rectangle where all four sides are equal. The area formula is simply A = s², where s is the side length. The perimeter is P = 4s, and the diagonal is d = s√2, derived from the Pythagorean theorem applied to two sides of the square.
Squares appear everywhere in daily life — floor tiles, picture frames, game boards, and property lots. Knowing the area helps with material estimation, while the diagonal is useful for fitting square objects through openings or determining the maximum internal dimension.
If you know the area and need to find the side, simply take the square root: s = √A. If you know the diagonal, the side is s = d / √2. This calculator works with any unit — enter meters, feet, or centimeters and interpret results accordingly.
Frequently Asked Questions
What is the formula for the area of a square?
Area = side × side, or A = s². For a square with side length 5, the area is 25 square units.
How do you find the diagonal of a square?
The diagonal of a square is d = s√2, where s is the side length. For a square with side 10, the diagonal is approximately 14.14.
How do you find the side length from the area?
Take the square root of the area: s = √A. If the area is 64, the side length is 8.
What is the difference between area and perimeter of a square?
Area measures the space inside the square (in square units), while perimeter measures the total distance around the outside (in linear units).