Statistics Kingdom

Distribution & Probability Calculators

Probabilities, quantiles, critical values and p-values for every common distribution — Normal, Binomial, T, Chi-Square, F, Poisson, Exponential and Weibull.

16 free calculators Step-by-step results No signup

Core tools 6 tools

Critical Value Normal, T, χ², F P-value statistic ⇄ p-value Probability P(A), P(A|B), Bayes ECDF empirical distribution Percentile value → percentile Surprisal -log₂ p, in bits

Distributions 8 tools

Normal z, probabilities, quantiles Binomial B(n, p) T (Student's) heavier tails Chi-Square χ²(df) F (Fisher-Snedecor) ratio of variances Poisson event counts, λ Exponential time between events Weibull lifetimes, reliability

Reference tables 2 tools

Z Table interactive table T Table interactive table