Random Generators
Random generators that draw fairly, from your browser's cryptographic generator: numbers, names, teams, coin flips and dice.
Random picks
- Random Number GeneratorEvery draw from this random number generator happens in your browser by crypto.getRandomValues, debiased by rejection sampling, with the arithmetic shown.
- Random Name PickerA random name picker for any list: one name or several, with or without repeats, every name given exactly the same chance, and a wheel that spins to the winner.
- Random Group GeneratorThe random group generator splits a list of names into a set number of groups, or into groups of a set size, and every possible grouping is exactly as likely as every other.
- Secret Santa GeneratorThe secret santa generator draws names so nobody gets their own, keeps couples apart, and gives every valid draw exactly the same chance.
Coins, dice and cards
- Flip a CoinFlip a coin for heads or tails, or flip up to 1,000 at once and see how the split and the longest run compare with chance.
- Dice RollerA dice roller for up to 20 dice from d4 to d100, with a modifier or notation like 2d6+3: every die, the total, and the exact chance of rolling that total or higher.
- Cribbage CalculatorType four cards and the starter, and this cribbage calculator gives the score of the hand or crib with every fifteen, pair, run, flush and nobs listed card by card.
More categories
- Math CalculatorsMath calculators that show their work: arithmetic, algebra, statistics, and a calculus calculator for derivatives and integrals, with exact answers in fractions and radicals where they exist.
- Geometry CalculatorsGeometry calculators for shapes, lines and angles, with the formula behind each answer explained.
- Chemistry Calculators, Physics and Lab ToolsChemistry calculators, physics calculators and molecular biology tools for the bench and the problem set.
- Conversion CalculatorsConversion calculators for unit conversion, number bases, Roman numerals and angles. The unit converter shows the factor it used and a conversion chart for the values around yours.
- Date and Time CalculatorsDate and time calculators for counting days, adding hours, converting time zones and reading other calendars.
- Business CalculatorsBusiness calculators for pricing a product and for the unit economics behind a company: margin, markup, break-even, ROI, CAC, LTV and churn.
- Everyday Cost CalculatorsCost calculators for what a meal, a drive or an appliance actually costs: tips, split bills, fuel, electricity and EV charging.
- Free Online ToolsFree online tools for codes and text, run in your browser with nothing uploaded.