Statistics calculators
Spread, z-scores, hypothesis screens, and random draws.
Statistics calculators on pancalc cover distributions, hypothesis tests, sample size, and descriptive measures. Each page explains which test assumptions apply and what the output cannot conclude on its own.
Use them for coursework, survey planning, and sanity-checking spreadsheet outputs. Statistical significance still requires thoughtful study design and interpretation.
When results look surprising, verify that input data meet the test requirements listed on the page.
9 calculators
Binomial & Chi-Square Calculator
Binomial probability P(X=k) and simplified chi-square statistic for a 2×2 table. Use the calculator above. Free browser tool. Free browser tool.
One-Way ANOVA (3 Groups) Calculator
Calculate sums of squares and the F statistic for three group means with equal sample sizes. Use the calculator above. Free browser tool.
Permutation & Combination Calculator
Compute nPr permutations and nCr combinations for counting problems. Use the calculator above. Use the calculator above. Free browser tool.
Poisson Distribution Calculator
Calculate exact and cumulative probabilities for counts from a Poisson process. Use the calculator above. Free browser tool. Free browser tool.
Random Number Generator
Generate a repeatable pseudo-random integer within a chosen inclusive range using a minimum, maximum, and changing roll value. Free browser tool.
Sample Size Power Analysis Calculator
Estimate per-group sample size for a two-sided two-group comparison from effect, SD, alpha, and power. Use the calculator above. Free browser tool.
Standard Deviation & Variance Calculator
Calculate the sample mean, sample variance, and sample standard deviation for up to six values. Use the calculator above. Free browser tool.
Two-Sample t-Test Calculator
Calculate pooled two-sample t statistic and degrees of freedom from group summaries. Use the calculator above. Free browser tool. Free browser tool.
Z-Score & Normal Distribution Calculator
Standardize a value relative to a mean and standard deviation and estimate its cumulative normal probability. Free browser tool. Free browser tool.