Measure how strongly two variables move together. Paste your x values on one line and your y values on another, and the tool computes the Pearson correlation coefficient r, a number between minus one and one. A value near one means a strong positive linear relationship, near minus one means a strong negative one, and near zero means little linear association. The formula divides the covariance of x and y by the product of their standard deviations, which normalizes the result so it does not depend on the units of your data. The tool also reports r squared, the share of variance in one variable explained by the other. This is the workhorse of regression, finance, and science. Remember that correlation is not causation. Everything is computed locally in your browser, so your paired data never leaves the page.
It measures the strength and direction of a linear relationship between two variables, ranging from minus 1 to plus 1.
Values near plus 1 or minus 1 show a strong relationship, near 0 shows little linear relationship, and the sign gives the direction.
No. A strong r shows two variables move together but does not prove that one causes the other.
Measure how strongly two variables move together. Paste your x values on one line and your y values on another, and the tool computes the Pearson correlation coefficient r, a number between minus one and one.
Yes. Correlation Coefficient Calculator is completely free, with no sign-up and no usage limits.
Yes. Correlation Coefficient Calculator runs in any modern web browser. There is nothing to download or install.
Yes. Correlation Coefficient Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.