Enter the average number of letters per 100 words and the average number of sentences per 100 words into the Coleman-Liau Index Calculator. The calculator will evaluate the Coleman-Liau Index. 

Coleman-Liau Index Formula

The following two example problems outline the steps and information needed to calculate the Coleman-Liau Index.

CLI = 0.0588*L – 0.296*S – 15.8

Variables:

  • CLI is the Coleman-Liau Index ( )
  • L is the average number of letters per 100 words 
  • S is the average number of sentences per 100 words 

How to Calculate Coleman-Liau Index?

The following steps outline how to calculate the Coleman-Liau Index.


  1. First, determine the average number of letters per 100 words. 
  2. Next, determine the average number of sentences per 100 words. 
  3. Next, gather the formula from above = CLI = 0.0588*L – 0.296*S – 15.8.
  4. Finally, calculate the Coleman-Liau 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.

average number of letters per 100 words = 600

average number of sentences per 100 words = 10

CLI = 0.0588*L – 0.296*S – 15.8 = ?