Annualized volatility (sample standard deviation of returns) from a price or return series you supply. Not advice.

One-way ANOVA across 2 to 12 groups: F statistic, degrees of freedom, p-value, eta squared and omega squared, with group means.

Mann-Whitney U test for two independent samples: U, exact p for small samples without ties or normal approximation, effect size.

Lottery odds: jackpot odds and every match tier for pick-k-of-N games with an optional bonus pool (Powerball, EuroMillions).

Fisher's exact test for a 2x2 table: two-sided and one-sided p-values from the hypergeometric distribution, plus odds ratio.

Chi-square goodness of fit (observed vs expected counts) or independence test on a table, with p-value and effect size.

Multinomial coefficient (arrangements of repeated items like MISSISSIPPI) and multinomial probability for given odds.

Expected value, variance, standard deviation and chance of profit for a list of payoffs with probabilities or weights.

Chance of a run: r successes in a row (or r identical outcomes) somewhere in n independent trials, like coin flips.

Exact binomial test of k successes in n trials vs a hypothesised probability, with p-values and the Clopper-Pearson CI.

Odds ratio, relative risk, risk difference and number needed to treat from a 2x2 table, each with a confidence interval.

Card odds: 5-card and 7-card poker hand probabilities, chance of hitting your outs by the river, blackjack natural odds.

Exact odds for dice pools: sum distribution, chance of reaching a target, mean and variance; supports drop-lowest like 4d6.

Exact pmf, cumulative and tail tables for geometric, negative binomial, hypergeometric, binomial and Poisson.

Gambler's ruin: probability of going broke before hitting a target, and expected number of bets, for repeated unit bets.

Playfair cipher encode or decode with a keyword; shows the 5x5 square and the digraphs. I and J are merged.

A1Z26 (A=1) and Polybius square number ciphers, both ways, with optional keyword square and ADFGX labels.

Convert text or bytes to and from binary, octal, hex, decimal, Base32 (RFC 4648), Base58 (Bitcoin) and Base64.

Sample size for a two-sample, one-sample or paired t-test from effect size, alpha and power; or the power for a given size.

Morse code encode or decode (ITU-R M.1677) with dot/dash timing in units and milliseconds at a chosen words per minute.