Correlation measures the strength and direction of the linear relationship between two variables. It ranges from -1 (perfect negative) to +1 (perfect positive), with 0 meaning no linear relationship.

R² (coefficient of determination) is the square of correlation. It represents the proportion of variance in Y explained by X. R² = 0.81 means 81% of Y's variance is explained by X.

Correlation vs causation?

Correlation does not imply causation. Two variables may be correlated due to a third variable or coincidence. Causation requires controlled experiments.

What does the regression line mean?

The regression line y = mx + b predicts Y from X. Slope (m) shows the change in Y per unit change in X. Intercept (b) is the predicted Y when X = 0.

What's a good correlation value?

|r| 0.7 is strong. But 'good' depends on context; in some fields, r = 0.5 is excellent.

Correlation Calculator

Calculate correlation coefficient and linear regression for paired data.

Enter Data Points

8 points

(1, 2)

(2, 4)

(3, 5)

(4, 4)

(5, 5)

(6, 7)

(7, 8)

(8, 9)

Weak Positive

r = 0

R² = 0% variance explained

Scatter Plot with Regression Line

Correlation (r)

R-Squared

Slope (m)

Intercept (b)

Regression Equation

y = 0x + 0

Documentation

Correlation & Regression

Correlation (r) measures linear relationship strength. Linear regression finds the best-fit line to predict Y from X.

Correlation

Regression

Frequently Asked Questions

How to Use

About the Correlation

What it calculates

This correlation solves mathematical and statistical problems using standard formulas. Calculate Pearson correlation (r) and linear regression.

When to use it

Use for homework, data analysis, exam prep, or quick verification of manual calculations.

Example

Adjust the inputs above to model your specific scenario with the Correlation.

Explore More

Correlation Calculator

Enter Data Points

r = 0

Scatter Plot with Regression Line

Regression Equation

Correlation & Regression

About the Correlation

Related Calculators

Mean, Median, Mode

Percentile

Standard Deviation

Variance

ANOVA (One-Way)

Bayes Theorem Calculator