Confidence interval, hypothesis test, p-value, and sample size calculators. Browse our free inference tools below — all calculators are instant, accurate, and require no sign-up.
ANOVA Calculator — Perform one-way ANOVA analysis online. Compute F statistic, p-value, eta-squared, omega-squared, and full ANOVA table with group summaries and visual comparison.
Bonferroni Correction Calculator — Calculate adjusted significance thresholds for multiple comparisons using Bonferroni, Šidák, and Holm corrections. Compare methods side-by-side with FWER tables.
Chi-Square Test Calculator — Perform chi-square goodness-of-fit and independence tests online. Get χ² statistic, p-value, Cramér's V, expected frequencies, and standardized residuals.
McNemar's Test Calculator — Perform McNemar's test for paired binary data. Compute chi-square statistic, exact binomial p-value, odds ratio, and compare correction methods on matched pairs.
Fisher's Exact Test Calculator — Perform Fisher's exact test on 2×2 contingency tables. Calculate exact p-value, odds ratio, relative risk, and view every possible table in the hypergeometric distribution.
Power Analysis Calculator — Calculate required sample size, achieved power, and Type II error for z-tests, t-tests, and chi-square tests. Cohen's d effect size reference and power curves included.
P-Value Calculator — Calculate p-values from z, t, chi-square, or F statistics. Supports two-tailed, left-tail, and right-tail tests with significance at multiple alpha levels.
Wilcoxon Rank-Sum Test Calculator — Perform the Wilcoxon rank-sum (Mann-Whitney U) test for non-parametric comparison of two groups. Get U statistic, z-score, p-value, effect size, and rank table.
T-Test Calculator — Perform one-sample, two-sample, Welch's, and paired t-tests online. Get t statistic, p-value, degrees of freedom, Cohen's d, and confidence intervals instantly.
Z-Test Calculator — Perform one-sample, two-sample, and proportion z-tests online. Calculate z statistic, p-value, confidence intervals, and compare against critical values.