Linear Regression Calculator

What is Linear Regression?

Linear regression is a statistical method for modeling the relationship between a dependent variable (y) and one or more independent variables (x). Simple linear regression uses one independent variable and finds the line y = bx + a that best fits the data by minimizing the sum of squared differences between observed and predicted values.

Linear regression finds the best-fitting straight line through a set of data points. Use our free calculator to calculate the slope, intercept, correlation coefficient (r), and R-squared value. Simply enter your x,y data points and get the regression equation with detailed step-by-step calculations and an interactive scatter plot.

Key Facts About Linear Regression

• *The regression line minimizes the sum of squared residuals (least squares)
• *Slope (b) tells you how much y changes for each unit increase in x
• *Intercept (a) is the predicted y value when x equals zero
• *Correlation coefficient (r) ranges from -1 to +1, measuring linear relationship strength
• *R-squared (R^2) is the proportion of variance in y explained by x
• *R^2 = r^2 for simple linear regression
• *Residuals are the differences between actual and predicted y values
• *A perfect fit has R^2 = 1 and all residuals equal zero

Frequently Asked Questions