Apothem Calculator

Enter the length of any side and total number of sides of the polygon into the calculator to determine the apothem.

Apothem Formula

The following formula can be used to calculate an apothem of any polygon.

a = S / (2*tan(180/n))

  • Where a is the apothem
  • S is the length of any side
  • n is the total number of sides

Apothem Definition

An apothem is defined as the distance between the center of a polygon and a center of any of the sides.

Apothem Example

How to calculate an apothem?

  1. First, determine the number of sides.

    Measure the total number of sides. For example a hexagon would have six sides.

  2. Next, determine the length of any side.

    Since the length of all sides on a polygon are equal, you can choose any side to measure.

  3. Finally, calculate the apothem.

    Input the side length and number of sides into the formula to calculate the apothem.


What is an apothem?

An apothem is the distance of a line that starts at the center of a polygon and ends at the center of one of the sides.

How do you find the apothem?

The apothem can be found using the formula above, but it also can be found using the number of sides and the circumradius.

apothem calculator
apothem formula