Dodecagon Area Calculator

Find the area of any regular dodecagon using this dodecagon area calculator.

Clear
Area93.530744regular hexagon
Side length6
Perimeter36
Apothem (inradius)5.196152
Circumradius6
Interior angle120°exterior 60°
Diagonals9

Working

Sides6 (hexagon)
Interior angle sum720°
Area from apothem½ × perimeter × apothem = 93.530744
Circumcircle area113.097336
Polygon fills82.699% of its circumcircle

The formula

A = n·s² ÷ (4·tan(π/n)), interior angle = (n−2)·180° ÷ n

Two ways to see the area

Split a regular n-gon into n triangles from the centre. Each has base s and height equal to the apothem, so the total area is ½ × perimeter × apothem — the same shape of formula as a circle’s ½ × circumference × radius. As n grows, the polygon becomes a circle and the two formulas converge.

Area scales with the square

Double every length in a flat shape and the area quadruples; triple them and it grows ninefold. Perimeter, being a length, scales in step with the sides. That mismatch is why bigger shapes enclose proportionally more area per unit of edge — and why a circle, having no corners at all, encloses the most area for a given perimeter of any shape.

Units

Whatever unit you enter, the area comes out in that unit squared and the perimeter in the unit itself. The calculator is unit-agnostic — enter centimetres and read cm and cm², or feet and read ft and ft². Just do not mix units between fields.