Square Calculator
Enter the side length of a square to find its area, perimeter and diagonal.
units
- 1
Input side length
5 - 2
Area = side × side
5 × 5 = 25
Formula
How this is calculated
A square is fixed by a single number: the side length (s), the common length of all four equal sides. Because every corner is a right angle and all sides match, that one input determines the entire shape. The calculator reads s, treats it as whatever linear unit you typed (cm, m, ft, in — it is unit-agnostic), and requires a positive value; zero or negative inputs produce no result.
Area is the surface the square encloses, found by multiplying the side by itself: Area = s², expressed in square units. The perimeter is the total distance once around the edge, and since all four sides are equal it is simply Perimeter = 4 × s. The diagonal joins two opposite corners, splitting the square into two right isosceles triangles; by the Pythagorean theorem it equals √(s² + s²) = s × √2, where √2 ≈ 1.4142.
Results are rounded to four decimals, so the diagonal (an irrational multiple of s) is approximate. The formulas assume a perfect square with exact right angles and flat, equal sides; they do not apply to rectangles, rhombi or any skewed quadrilateral.
Examples
| Input | Result |
|---|---|
| side = 5 | Area = 25, Perimeter = 20, Diagonal ≈ 7.0711 |
About this calculator
A square is a special rectangle (and a special rhombus) in which all four sides are equal and all four angles are right angles. Because every side has the same length, its area is the side squared and its perimeter is four times the side.
The diagonal splits the square into two right isosceles triangles, so by the Pythagorean theorem it equals the side multiplied by √2 (about 1.4142). Squares are everywhere in tiling, packaging and grid layouts, making these quick conversions handy.
Frequently asked questions
Multiply the side length by itself (s²). A square with side 5 has an area of 25 square units.
The diagonal is the hypotenuse of a right triangle whose two legs are both the side s, so by the Pythagorean theorem it equals √(s² + s²) = s√2.
Yes. A square satisfies every property of a rectangle (four right angles) with the extra condition that all sides are equal.
Also known as
TG we-Calculate Editorial Team. (2026). Square Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/square-calculator
TG we-Calculate Editorial Team. "Square Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/square-calculator.
TG we-Calculate Editorial Team, "Square Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/square-calculator
@misc{wecalculate_square_calculator, title = {Square Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/square-calculator}}, year = {2026}, note = {TG we-Calculate} }
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