Square Area Calculator

What Is the Area of a Square?

The area of a square is the amount of two-dimensional space inside its four equal sides. If you know the side length, diagonal, perimeter, circumradius, or inradius, you can find the area with a simple formula. Our calculator works in real time and shows step-by-step math.

For related geometry tools, see our Square Calculator and Square Diagonal Calculator.

Square Area Formulas

From side length $a$:

$$A = a^2$$

From diagonal $d$:

$$A = \frac{d^2}{2}$$

From perimeter $P$:

$$A = \frac{P^2}{16}$$

Worked Example

A square has side length 7 units. Its area is $7^2 = 49$ square units. The diagonal is $7\sqrt{2} \approx 9.899$ units.