Area of a Square Calculator

A = s² where s is the side length.

Inputs

Result

Loading calculator…
—

How to use this calculator

  • Enter the side length.
  • Read the area, perimeter, and diagonal.

About this calculator

The simplest area formula. Squares are special rectangles where both sides are equal, and special rhombuses where all four sides are equal AND all corners are right angles. The diagonal of a square is s√2 ≈ 1.414s.

Frequently asked

How do I find the side from the area?+
s = √A. So an 81-unit² square has side √81 = 9.
What is the diagonal of a square?+
d = s · √2 ≈ 1.414s. So a 10-unit square has diagonal ~14.14.
How does a square differ from a rhombus?+
Both have 4 equal sides. A square also has 4 right angles. A rhombus only requires equal sides.
Can the side be a decimal?+
Yes — any positive real number. The formula handles decimals identically.
What units does the area come out in?+
Square of whatever unit you input. 5 ft side → 25 ft². 5 m → 25 m².

Related calculators

Area of a Rectangle Calculator
A = length × width.
Area of a Circle Calculator
Calculate the area of a circle given its radius (or diameter). A = πr².
Area of a Rhombus Calculator
A = (d₁ × d₂) / 2 — half the product of the diagonals.
Square Perimeter Calculator
P = 4s. Four equal sides.
Cube Volume Calculator
V = s³. Six equal square faces.
Pythagorean Theorem Calculator
a² + b² = c². Solve for hypotenuse or missing leg of a right triangle.

More tools you might like

Hand-picked tools that pair well with this one — same audience, same intent.

Area of a Rectangle Calculator
Calc

A = length × width.

Area of a Circle Calculator
Calc

Calculate the area of a circle given its radius (or diameter). A = πr².

Area of a Rhombus Calculator
Calc

A = (d₁ × d₂) / 2 — half the product of the diagonals.

Square Perimeter Calculator
Calc

P = 4s. Four equal sides.

Cube Volume Calculator
Calc

V = s³. Six equal square faces.

Body Surface Area (BSA) Calculator
Health

Estimate body surface area in m² using Mosteller and Du Bois formulas — for clinical reference, anesthesia dosing, and physiologic indexing.