Point-Biserial Correlation Calculator
Measure the relationship between a two-group variable and a continuous one. Paste the 0/1 values and the matching continuous values in the same order.
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What point-biserial measures
The point-biserial correlation measures how strongly a two-group variable relates to a continuous one, for example whether answering a test item correctly relates to the total score. It is mathematically a Pearson correlation with one variable coded as 0 and 1, so it runs from minus 1 to plus 1 and is read the same way.
Formatting your data
Enter the binary variable as 0s and 1s, then the continuous values in the same respondent order. The two lists must be the same length. A positive result means the group coded 1 tends to have higher continuous scores.
Frequently asked questions
Where is this used in testing?
Item analysis uses point-biserial correlation as a discrimination index: it shows whether students who got an item right also scored higher on the test overall.
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