Enter the diameter of the medulla and the diameter of the hair into the Medullary Index Calculator. The calculator will evaluate the Medullary Index. 

Medullary Index Formula

The following two example problems outline the steps and information needed to calculate the Medullary Index.

MI = M / H

Variables:

  • MI is the Medullary Index ( )
  • M is the diameter of the medulla 
  • H is the diameter of the hair 

How to Calculate Medullary Index?

The following steps outline how to calculate the Medullary Index.


  1. First, determine the diameter of the medulla. 
  2. Next, determine the diameter of the hair. 
  3. Next, gather the formula from above = MI = M / H.
  4. Finally, calculate the Medullary Index.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

diameter of the medulla = 1

diameter of the hair = 3

MI = M / H = ?