What is the Coefficient of Determination (R²) Calculator?

The R² Calculator is a statistical tool that helps users determine how well a regression line fits a dataset. By entering X (independent) and Y (dependent) values, the calculator computes the slope and intercept of the best-fit line, predicted Y values, the total and residual sums of squares, and the R² value. The R² value indicates the proportion of the variance in the dependent variable explained by the independent variable, helping users evaluate the accuracy and predictive power of their model.

How to Use:

1. Enter X Values (comma-separated): Input the independent variable data points, e.g., 1, 2, 3, 4, 5.
2. Enter Y Values (comma-separated): Input the dependent variable data points corresponding to each X, e.g., 2, 4, 5, 4, 5.
3. Click “Calculate”: The calculator computes the slope, intercept, predicted Y values, residuals, total sum of squares (SST), residual sum of squares (SSR), and the R² value.
4. Review Result: The output displays the regression equation, SST, SSR, R², and a detailed calculation table showing X, actual Y, predicted Y (Ŷ), and squared residuals (Y − Ŷ)², allowing you to assess the goodness-of-fit of your data.