Correlation Calculator
Calculate Pearson’s r and r² for paired numeric data, with a scatter plot and sample statistics.
Scatter plot
| X | Y |
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Data pairs (first 100)
| Original position | X | Y | X − x̄ | Y − ȳ | (X − x̄)(Y − ȳ) |
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Correlation does not imply causation. Pearson r measures linear association; outliers can affect it.
A QUICK WALKTHROUGH
How to use this tool
- Enter X and Y lists of equal length, separated by commas, spaces or new lines.
- Choose whether to reject missing values or omit their entire pair.
- Calculate and review the plot, statistics and paired data.
Pearson’s linear correlation
r = Σ((x−x̄)(y−ȳ)) / √(Σ(x−x̄)² Σ(y−ȳ)²). Sample covariance and standard deviations use n−1.
Input and missing values
At least two complete pairs are required. Use NA, null or ? for missing values; no values are inferred from blank separators. Both lists must have equal length before any pairs are omitted. Maximum 10,000 positions per list; finite decimal or scientific numbers with absolute value ≤ 1e12. Constant columns are rejected.
GOOD TO KNOW
Common questions
Does correlation imply causation?
No. Pearson’s r describes a linear association, not causation. Outliers can change it substantially; a value near zero does not rule out a nonlinear relationship.
Are my values uploaded?
No. This calculation and its scatter plot run in your browser.