Linear Regression Calculator

Free linear regression calculator. Find slope, intercept, correlation coefficient, R-squared, and make predictions. Includes scatter plot visualization.

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5 data points

y = 0.6x + 2.2
0.6

± 0.282843

2.2

± 0.938083

0.774597

Moderate positive

0.6

60.0% variance explained

3

4

0.894427

2.4

Predict Y from X

Scatter Plot with Regression Line

Data Points
Regression Line

Linear Regression Formulas

Slope (m): m = Σ(x-x̄)(y-ȳ) / Σ(x-x̄)²
Intercept (b): b = ȳ - m·x̄
Correlation (r): r = Σ(x-x̄)(y-ȳ) / √[Σ(x-x̄)²·Σ(y-ȳ)²]
R-squared: R² = r²
Prediction: ŷ = mx + b

Interpreting Results

Slope: For each unit increase in X, Y changes by the slope value

Intercept: The predicted Y value when X = 0

R² (Coefficient of Determination):

  • 0.9 - 1.0: Very strong fit
  • 0.7 - 0.9: Strong fit
  • 0.5 - 0.7: Moderate fit
  • 0.3 - 0.5: Weak fit
  • 0.0 - 0.3: Very weak fit

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