Correlation Coefficient Calculator
Calculate Pearson correlation coefficient and coefficient of determination (R²) from paired data
About this calculator
The Correlation Coefficient Calculator computes the Pearson correlation coefficient (r) and coefficient of determination (R²) from paired datasets. This powerful statistical tool measures the strength and direction of linear relationships between two variables, with values ranging from -1 to +1. It's essential for researchers, analysts, and students conducting data analysis, hypothesis testing, and predictive modeling across fields like psychology, economics, and natural sciences.
How to use
Enter your paired data points in two columns or lists representing your X and Y variables. Ensure both datasets have equal length and contain numerical values. Click calculate to instantly obtain the Pearson correlation coefficient and R² value, along with interpretation of the relationship strength.
Frequently asked questions
What does a correlation coefficient of 0.8 mean?
A correlation of 0.8 indicates a strong positive linear relationship, meaning variables tend to increase together with high predictability.
What's the difference between r and R²?
R (correlation coefficient) shows relationship strength and direction, while R² shows the percentage of variance one variable explains in another.
Can correlation coefficients prove causation?
No, correlation only measures association strength. High correlation doesn't imply that one variable causes changes in the other variable.