Dice Roller
Roll any number of dice with any number of sides — 2d6, 4d6, 1d20 with a modifier — and see the total, every individual die, and how likely that total was.
Each die is drawn from a seeded generator, so the same seed rolls the same dice; change the seed to roll again.
How the dice roller works
Each die is drawn from a seeded generator, so the same seed rolls the same dice; change the seed to roll again. Alongside the roll the calculator gives the odds: the lowest and highest possible totals, the average (each die averages (sides + 1) ÷ 2), and where your roll sits. Totals from several dice cluster in the middle — with 2d6 there are six ways to make 7 but only one to make 2, which is why 7 comes up six times as often.
Formula: total = Σ dice + modifier; average = n × (sides + 1) / 2 + modifier
Worked examples
| Inputs | Total | Note |
|---|---|---|
| 2d6 — two ordinary dice | 7 | totals cluster around 7 |
| 1d20 + 5 — a skill check | 19 | range 6 to 25 |
| 4d6 — rolling a character stat | 17 | average 14 |
FAQFrequently asked questions
What does 2d6 mean?
Two dice of six sides. The first number is how many dice, the second how many faces — so 1d20 is a single twenty-sided die.
Why do totals cluster in the middle?
There are more ways to make a middling total. With two dice there are six combinations that make 7 and only one that makes 2.
Are the rolls fair?
Every face is equally likely from the seeded generator. It is reproducible by design — the same seed rolls the same dice — so it is for play, not for gambling.
How do I roll again?
Change the seed. Any word or number gives a new roll.
What is the modifier for?
Tabletop games often add a bonus to the roll: 1d20 + 5 means roll a d20 and add five.
Where these figures come from
- NIST Digital Library of Mathematical Functions — reference definitions for elementary and special functions
- Wolfram MathWorld — definitions and formulas for every topic on this page
- NIST/SEMATECH e-Handbook of Statistical Methods — the statistical formulas (mean, variance, z, confidence intervals, sample size)
- Common Core State Standards — Mathematics — the terms and methods taught in US schools
Last checked: September 2026. Formulas are fixed by mathematics and do not change with tax years or regulations.