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Regular Polygon Calculator

Calculate the area and perimeter of a regular polygon from the number of sides and the side length.

 

 

Area
Perimeter

About this calculator

Use this calculator to find the area and perimeter of a regular polygon: a shape with n equal sides and n equal interior angles. Enter at least 3 sides. Common cases are an equilateral triangle (3), a square (4), a regular pentagon (5), a hexagon (6), and an octagon (8).

The formulas are: area = n s² / (4 tan(π / n)) and perimeter = n s. The formula uses the apothem implicitly through the tangent of the central half-angle.

Use any length unit for the side length. Perimeter stays in that unit; area is in that unit squared.

Sides: Number of sides, an integer of at least 3. 6 is a hexagon.

Side length: Length of one side.

Area: Interior of the regular polygon.

Perimeter: Total length around the polygon, n times the side.