Regular Polygon Calculator

Find the area, perimeter and angles of any regular polygon.

What the Regular Polygon Calculator does

A regular polygon has equal sides and equal angles. Its area is half the perimeter times the apothem — the perpendicular distance from the centre to a side. As the side count rises the shape converges on a circle.

Formula

  • Area = (n × s²) ÷ (4 × tan(π ÷ n))
  • Interior angle = ((n − 2) × 180) ÷ n
  • Apothem = s ÷ (2 × tan(π ÷ n))

Inputs explained

InputUnitRequiredNotes
Number of sidesnumberYesAccepts 3 or more.
Side lengthnumberYesAccepts more than 0.

How to use it

  1. Enter Number of sides and Side length.
  2. Select Calculate.

Worked example

A regular hexagonal tile with 10 cm sides.

Sides
6
Side length
10

Area ≈ 259.81 cm², perimeter 60 cm, interior angle 120°.

Frequently asked questions

Why do hexagons tile so well?

Their 120° interior angle divides evenly into 360°, so three meet perfectly at every vertex with no gaps — which is why honeycombs use them.

Related calculators