Area of a Square Calculator

A = s² where s is the side length.

Inputs

Result

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General calculation reads

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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.

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