Probability Calculators

Last updated: October 2026

Poker Hand Probability Calculator

Calculate the probability of being dealt any classic five-card poker hand from a standard 52-card deck.

Computes the probability of observing exactly k events in a fixed interval when events occur at a known average rate.

Calculate combinations (nCr) and permutations (nPr), with or without replacement, for counting and probability problems.

Find the probability of exactly, at most, at least, fewer than or more than k successes in n independent trials with success probability p.

Work out the jackpot odds of a lottery from how many numbers are drawn from how big a pool, including bonus-ball games like Powerball.

Determine the statistical power of a hypothesis test given effect size, sample size, and alpha level.

Calculate the probability that multiple dice produce a specific sum, or a sum greater or less than a target.

Compute the chi-square test statistic contribution for one observed-vs-expected category pair using χ² = (observed − expected)² / expected.