Geometry GlanceSources

Square calculator

cm

Advanced

Changing a measurement unit keeps its number: 3 cm becomes 3 m. Unit for all measurements applies to every input and the result. Result unit converts only the answers.

Four equal sides and four right angles.

Number format

Use a decimal point or comma, without thousands separators. Up to 15 significant digits and 64 characters; no fractions or expressions.

aa

Not to scale

Enter your measurements to see the results.

No personal result is available. These are the square formulas and conditions.

Formulas and conditions

Square

A square with a marked right angle and adjacent sides both labelled a.aa
Area
A=a2
Perimeter
P=4a

a side length · A area · P perimeter

All four sides equal a, with four right angles. a > 0.

Equal sides alone are not enough: a slanted rhombus is not a square.

Diagrams are schematic, not to scale.

A square is the rectangle case L = W = a. One side determines both its area and perimeter.

Squaring a side produces square units. Multiplying the side by four keeps length units.

Use the same length unit throughout a formula. Convert mixed measurements first. Length and perimeter use units such as cm; area uses cm²; volume uses cm³. Decimal examples below are rounded to at most six significant figures, with ≈ marking an approximation.

Worked example: A square with side 2.5 cm

  1. A = 2.5² = 6.25 cm².
  2. P = 4 × 2.5 = 10 cm.

Substitute L = W = 2.5 into the rectangle formulas: the results agree.

Formula sources

Formulas are checked against these references. The explanation, diagrams and worked calculations here are authored for Geometry Glance.