Enter the probability of agreement and the probability of random agreement into the Calculator. The calculator will evaluate the Kappa Index. 

Kappa Index Formula

KI = (P0-Pe)/ (1-Pe)


  • KI is the Kappa Index ()
  • P0 is the probability of agreement
  • Pe is the probability of random agreement

To calculate Kappa Index, subtract the probability of random agreement from the probability of agreement, then divide the result by the result of 1 minus the probability of random agreement.

How to Calculate Kappa Index?

The following steps outline how to calculate the Kappa Index.

  1. First, determine the probability of agreement. 
  2. Next, determine the probability of random agreement. 
  3. Next, gather the formula from above = KI = (P0-Pe)/ (1-Pe).
  4. Finally, calculate the Kappa 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.

probability of agreement = 40

probability of random agreement = 250