Correlation Coefficient Calculator

About this calculator

This calculator finds the Pearson correlation coefficient (r) for a set of paired x/y values, measuring how strongly two variables move together on a scale from -1 (perfect negative relationship) to +1 (perfect positive relationship), with 0 meaning no linear relationship at all.

Researchers and students use it to check whether two variables — like study hours and test scores, or temperature and ice cream sales — are related, and analysts use it as a first check before building a regression model. Paste in paired data and it returns r along with the underlying counts.