Calculator
Enter the values below. Every quantity identifies its unit or meaning.
Formula / method
r = Σ[(x−x̄)(y−ȳ)] / √[Σ(x−x̄)² Σ(y−ȳ)²].
r = Σ[(x−x̄)(y−ȳ)] / √[Σ(x−x̄)² Σ(y−ȳ)²].
How to use this calculator
What to enter
Enter or select the following as requested: X values; Y values. Follow the units, valid ranges, examples, and options displayed beside each field.
What the result means
The output describes the relationship or fitted trend in the data entered. Correlation does not by itself establish causation, and a fitted model may be unreliable outside the observed data range.
When to use it
Use this to explore association or estimate a trend from paired data. Check sample size, outliers, assumptions, and whether the model is appropriate for the data.