Regular Polygon Calculator
Calculate area, perimeter, angles, and properties of regular polygons
About this calculator
This Regular Polygon Calculator helps you find essential measurements and properties of any regular polygon, including area, perimeter, interior angles, exterior angles, and side lengths. Whether you're a student learning geometry, an architect designing structures, or an engineer working on projects, this tool provides accurate calculations for polygons with 3 to any number of equal sides. Simply input the known values, and instantly get comprehensive results for all polygon properties.
How to use
Enter the number of sides for your regular polygon and provide one known measurement (such as side length, area, or perimeter). Select your preferred units and click calculate. The tool will automatically compute all other properties including area, perimeter, interior angles, exterior angles, and radius of circumscribed and inscribed circles.
Frequently asked questions
What is a regular polygon?
A regular polygon is a geometric shape with equal sides and equal angles. Common examples include equilateral triangles, squares, pentagons, and hexagons.
How do you calculate the area of a regular polygon?
The area formula is: A = (perimeter × apothem) ÷ 2, or A = (n × s² × cot(π/n)) ÷ 4, where n is sides and s is side length.
What's the difference between interior and exterior angles?
Interior angles are inside the polygon. Exterior angles are formed between one side and the extension of an adjacent side, always totaling 360° for any polygon.