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Linear Regression Calculator

Fit a least-squares line and report the slope, intercept, and coefficient of determination.

Slope
Intercept

About this calculator

Use this calculator to fit a straight line y ≈ intercept + slope × x to paired observations. Typical uses are calibration lines, trend of a score with time, or a simple prediction sketch.

The line minimises the sum of squared vertical residuals. Slope = Sxy / Sxx and intercept = ȳ − slope × x̄. R² is the square of Pearson's r here (the share of y variance along the line). The default pairs give a clear upward slope and R² near 0.81.

This is ordinary least squares for one predictor, not multiple regression, and not a robust fit against outliers. x needs some spread. A high R² is not proof of a causal line.

x values: Predictor values, comma- or space-separated.

y values: Response values, same length as x, in the same order.

Slope: Change in y per one-unit change in x.

Intercept: Predicted y when x = 0.

R²: Coefficient of determination, from 0 to 1.