How to use this calculator
Enter paired rows for simple regression or x1,x2,y rows for two predictors.
Formula and method
OLS minimizes Σ(y−ŷ)². Simple slope=Sxy/Sxx. Mean CI ŷ±t*s√(1/n+(x−x̄)²/Sxx); prediction interval adds 1 under square root.
Worked example
For (1,2),(2,4),(3,6), slope 2, intercept 0, and predicted y at x=4 is 8.
Assumptions and supported scope
Simple 3–500 rows, two-predictor 4–500 rows. Exact singular designs rejected. Intervals only for simple regression and rely on stated OLS error assumptions; extrapolation flagged.
Method references
Method and worked example checked against the calculator implementation. About our methods · Report a correction