How to Calculate Regression Line
What is Regression Line?
Regression analysis finds the best-fit line (y = mx + b) through a set of data points. It minimizes the sum of squared differences and is fundamental to predictive modeling.
Formula
m = (n×Σxy - Σx×Σy) / (n×Σx² - (Σx)²); b = (Σy - m×Σx) / n
Step-by-Step Guide
- 1Input data points (x, y)
- 2Calculate sums: Σx, Σy, Σxy, Σx²
- 3Compute slope m and intercept b using the formula
Worked Examples
Input
Points: (1,2), (2,4), (3,5)
Result
y ≈ 1.5x + 0.5
Least squares regression line
Common Mistakes to Avoid
- ✕Confusing correlation with causation
- ✕Not checking for outliers affecting the line
Ready to calculate? Try the free Regression Line Calculator
Try it yourself →