Calculate the Pearson correlation coefficient (r) and the coefficient of determination (R²) between two variables, with an interpretation of strength and direction.
How it works
- Paste a comma-separated list of values for the X variable.
- Paste a matching length list of values for the Y variable.
- The calculator processes the lists to define Pearson r correlation and R-squared variance.
Frequently asked questions
What is a strong correlation?
As a rough guide: |r| above 0.7 is strong, 0.4–0.7 is moderate, below 0.4 is weak. Context matters — standards differ between fields.
Does correlation imply causation?
No. A strong correlation may be coincidental, driven by a third variable, or reverse-caused. Correlation alone never proves causation.
What does R² mean?
It is the proportion of variation in Y explained by X. An R² of 0.64 means 64% of the variance in Y is accounted for by its linear relationship with X.