Calculate OLS slope (b), standard error, t-stat, p-value, and 95% confidence intervals.
Regression Intercept Calculator – Baseline Origin & Y-Intercept
Determine baseline Y-intercept (a), horizontal X-intercept root, and baseline standard error.
Regression Calculator – Multi-Model Curve Fitting & Predictor
Free multi-model Regression Calculator. Fit Linear (Y=a+bX), Exponential, Logarithmic, Power, and Quadratic models. Compare R², find best fit, and predict Y.
Ratio Calculator — Solve Proportions, Simplify & Scale Ratios Free
Solve for X in proportions (A:B = C:X), simplify ratios to lowest whole numbers, scale ratios, and divide amounts into proportional shares online free.
R-Squared Calculator – Coefficient of Determination & Model Fit
Calculate coefficient of determination (R²), Adjusted R², SST, SSR, and SSE variance components.
Quartile Calculator – Q1, Q2, Q3 & Five-Number Summary
Calculate Q1, Q2 (median), Q3, IQR, and five-number summary with Tukey hinges, Excel QUARTILE.INC, and Moore & McCabe methods.
Quadratic Equation Solver | Step-by-Step Formula, Roots & Vertex
Solve ax² + bx + c = 0 with discriminant analysis, real and complex roots, vertex coordinates, and step-by-step working.
Probability Calculator — Binomial, Combinations & Event Odds
Calculate single event probability, independent events, binomial distributions (n, k, p), permutations (nPr), and combinations (nCr) free online.
Polynomial Solver | Find Real & Complex Roots (Cubic & Quartic)
Find real roots and factors for quadratic and cubic polynomials using Cardano’s method and Rational Root Theorem.
Poisson Distribution Calculator – Exact & Cumulative Probabilities
Calculate exact probability P(X = k), cumulative CDF, tail risk, and arrival rate statistics.