Calculators
Correlation Coefficient Calculator
Calculate the Pearson correlation coefficient (r) for two paired datasets locally in your browser.
Enter two paired datasets with the same number of values in the same order, separated by commas, spaces, or new lines. Uses Pearson r for linear association. The calculation runs locally in your browser; your values are not uploaded or stored.
Find a correlation coefficient without uploading anything.
Enter two paired datasets with the same number of values in the same order to see Pearson r, R-squared, both means, and the strength and direction of the linear relationship with the formula shown. Everything runs locally in your browser, so your values are not uploaded or stored.
Frequently Asked Questions
Everything you need to know about this tool, how it works, and privacy.
What does the correlation coefficient calculator show?
Enter two paired datasets with the same number of values in the same order. The calculator returns Pearson r from -1 to 1, R-squared, the pair count, both means, and a strength and direction interpretation with the calculation shown. For example, X 1, 2, 3, 4, 5 with Y 2, 4, 5, 4, 6 gives r near 0.85, a strong positive linear relationship.
Which formula does the correlation coefficient calculator use?
It uses Pearson r = sum of ((x minus x-bar) times (y minus y-bar)) divided by the square root of (sum of (x minus x-bar) squared times sum of (y minus y-bar) squared). R-squared is r squared. Values near 1 or -1 mean a strong linear relationship, while values near 0 mean little linear relationship; correlation does not prove that one variable causes the other.
Which inputs are accepted?
Enter at least two numbers in each dataset with the same count in both, up to 10000 values each, where every value is from -1000000000 to 1000000000. Separate values with commas, spaces, or new lines. Missing values, non-numeric text, mismatched counts, fewer than two values, constant datasets with no variation, and values outside these ranges show a clear error instead of a result.
Do my numbers stay private?
Yes. The calculation and copy action run locally in your browser. CodeASystem does not upload or store the values you enter.