Linear Regression Calculator
Fit a least-squares line through your data points: slope, intercept, correlation r, r² and predictions — with the scatter plot and fit line drawn live.
Example values are shown — change any of them and the answer updates live.
Format: x, y — one pair per line.
Best-fit line
y = 0.6x + 2.2
5 points, least-squares fit.
Correlation r0.7746
r²0.6
Predict y at x =7 (x=8)
Least-squares fit. Correlation ≠ causation — always.
Prediction
At the mean of x
4
x̄ = 3
Extrapolate x + 5
7
x = 8
Extrapolating beyond your data gets less trustworthy the further you go.
Extrapolating beyond your data gets less trustworthy the further you go.
Best-fit line
Step 1 · m (slope)
m = Sxy ÷ Sxx
n=5
0.6
Step 2 · b (intercept)
b = ȳ − m·x̄
x̄=3
2.2
Step 3 · r (correlation)
r = Sxy ÷ √(Sxx·Syy)
0.7746
Exact arithmetic — computed instantly in your browser.