Dice roller & probability calculator
Roll fair dice, inspect every result and calculate exact sum distributions and target probabilities. Save favorite expressions on this device.
One dice group plus an optional constant, e.g. 2d6+3. 1–100 dice, 2–100 sides, modifier within ±1,000,000. No exploding or reroll rules.
Latest roll
Sum distribution
All outcomes
| Total | Probability |
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Data stays in this browser. Saved games and presets can be lost when browser data is cleared; export important records.
Questions and rules
Which expressions are supported?
One group of fair independent dice plus or minus one integer, such as 2d6+3. Use 1–100 dice, 2–100 sides and a modifier within ±1,000,000. Exploding, reroll, advantage and game scripts are not supported.
What is the chance of at least 8 on 2d6?
15 of the 36 equally likely combinations total at least 8, about 41.6667%. The tool counts outcomes as exact integers, then converts to decimals for display.
Are rolls fair?
Rolls use the browser’s secure random source and rejection sampling to avoid modulo bias. This is for tabletop use and rules exploration, not certified lotteries or regulated competition.
Where are history and presets saved?
Up to 50 rolls and 10 presets stay in this browser. Copy expressions or results, or export a PNG. Clearing history retains presets; clearing website data deletes both.