Correlation Coefficient Calculator

This calculator measures how closely two sets of paired numbers move together, using Pearson's r. Paste your X values and your Y values in matching order and it returns r, r squared, the direction and strength of the relationship, the sample covariance and the least-squares regression line. The two lists must be the same length, and neither can be a single value repeated, because a list with no spread has nothing to correlate. Correlation is not causation, and r only detects straight-line relationships, so a strong curved pattern can still score close to zero.