Enter the variance of interest and the unwanted variance into the calculator to determine the intraclass correlation.

ICC (Intraclass Correlation) Formula

The following equation is used to calculate the intraclass correlation.

ICC = VOI / (VOI + UV)
  • Where ICC is the intraclass correlation
  • VOI is the variance of interest
  • UV is the unwanted variance

To calculate intraclass correlation, divide the variance of interest by the sum of the variance of interest and the unwanted variance.

What is a ICC (Intraclass Correlation)?


Intraclass correlation is a statistical measure of the relationship between different measurements of a single variable. It is often used to assess the degree of consistency or agreement between different raters, judges or observers.

CC measures the degree to which two different sets of variables are related. For example, you may be interested in understanding how well income and education predict performance on a test. The ICC would tell you how much overlap there is between these two groups of variables so that you could interpret your findings accordingly.

This statistic can also be used to study group differences, such as comparing men and women on the same test (or any other combination of groups).

The ICC ranges between 0 and 1, with higher scores indicating greater association between two variables. An ICC value closer to 0 indicates very little overlap.