Apothem of a Regular Polygon Calculator

In a polygon, a line to the midpoint of one of the sides from the center is called as apothem. Find the apothem of a regular polygon or circumradius of the incircle using this free online calculator.

Apothem of a Regular Polygon Calculation

  • Select a polygon:

  • Side Length or Circumradius:

  • Side Length (a):

  • Circumradius (R):

  • number of sides (n):

  • Apothem of a regular polygon (r):

Formula Used:
r = a / [2 tan(π / n)]
r = R cos(π / n)
r = Apothem of regular polygon
R = Circumradius
π = 3.14159...
a = Side length
n = Number of side