Linear regression, correlation, R-squared, and curve fitting calculators. Browse our free regression tools below — all calculators are instant, accurate, and require no sign-up.
Coefficient of Determination (R²) Calculator — Calculate R², adjusted R², SS decomposition (SST/SSR/SSE), F-statistic, standard error, and residual analysis. Full ANOVA decomposition with interpretation guide.
Correlation Calculator — Calculate Pearson and Spearman correlation coefficients, R², covariance, significance testing, z-scores, and ranks from X/Y data. Full statistical analysis.
Cubic Regression Calculator — Fit Y = aX³ + bX² + cX + d with R², inflection point, critical points, end behavior analysis, and residual table. Comparison to linear fit.
Exponential Growth Prediction Calculator — Predict future values with exponential growth/decay. Doubling time, half-life, Rule of 70, milestone table, growth trajectory, discrete & continuous compounding.
Exponential Regression Calculator — Fit Y = ae^(kx) or Y = abˣ with R², doubling time/half-life, growth rate, log-scale residuals, and growth projection table.
Linear Regression Calculator — Calculate the best-fit line (OLS), slope, intercept, R², correlation, residuals, and prediction confidence intervals from X/Y data points.
Matthews Correlation Coefficient (MCC) Calculator — Calculate MCC from confusion matrix with full metrics: accuracy, F1, precision, recall, specificity, Cohen's kappa, informedness, markedness, and visual confusion matrix.
Pearson Correlation Calculator — Calculate Pearson's r with step-by-step computation, Fisher z confidence intervals, t-test significance, covariance, and full deviation table.
Polynomial Regression Calculator — Fit polynomials of any degree (1-8) with R², adjusted R², AIC/BIC, coefficient table, residuals, and automatic degree comparison for model selection.
Quadratic Regression Calculator — Fit Y = aX² + bX + c to data with R², vertex, roots, discriminant, residual analysis, and comparison to linear fit.
Quartic Regression Calculator — Fit a fourth-degree polynomial (Y=aX⁴+bX³+cX²+dX+e) with R², critical points, inflection points, ANOVA, residuals, and degree comparison.
Residual Analysis Calculator — Compute residuals, standardized residuals, leverage, Cook's distance, Durbin-Watson, skewness, kurtosis, and outlier detection for regression diagnostics.
Spearman's Rank Correlation Calculator — Calculate Spearman's ρ with rank table, tie correction, t-test significance, Σd² breakdown, and Spearman vs Pearson comparison.