Overview
What Is a Correlation Coefficient?
The correlation coefficient (Pearson's r) measures the strength and direction of a linear relationship between two variables, ranging from -1 to 1.
Measure the relationship between two data sets.
The correlation coefficient (Pearson's r) measures the strength and direction of a linear relationship between two variables, ranging from -1 to 1.
Useful for understanding whether and how strongly two variables are related.
Type numbers separated by commas.
Type the corresponding Y numbers, same count as X.
The result updates automatically.
The strength and direction of a linear relationship between two variables.
It indicates no linear relationship between the variables (though a non-linear relationship could still exist).
As one variable increases, the other tends to decrease.
No, correlation only shows association, not that one variable causes changes in the other.
Values above 0.7 or below -0.7 are often considered strong, though interpretation varies by field.
Yes, they must be paired - each X value corresponds to a Y value at the same position.
No, calculations happen entirely in your browser.
Pearson's correlation coefficient (Pearson's r) is the formal name for this measure.
Yes, this occurs with a perfect linear relationship, though it's rare with real-world data.
Yes, completely free with no sign-up required.