Dice Roller
Roll any number of dice with any number of sides and see each roll and the total.
Formula last reviewed 15 September 2026 · How we verify our calculators
Total
- Each die
- 4, 3
Updates live as you type
Frequently asked questions
Roll up to 20 dice at once, each with anywhere from 2 to 100 sides — so a D6, D20 or any custom die all work.
It makes a roll reproducible: the same seed and settings always give the same result. Change the seed to roll again, or share it so others see your exact roll.
Yes. Set the sides to 20 for a D20, 12 for a D12, and so on. Set the number of dice to roll several at once and read the total.
Each side has an equal chance using a quality pseudo-random algorithm, so rolls are statistically fair for games and decisions.
Two dice, and why seven comes up most
Rolling 2 dice of 6 sides with seed 42 gives 4 and 3 — a total of 7.
Seven is the most likely total on two dice, and the reason is worth understanding because it explains a great deal about how probability behaves when you add random quantities together.
The distribution of two dice
A single die is uniform — each face has probability 1/6, and no outcome is more likely than any other.
Two dice summed are not uniform at all. There are 36 equally likely combinations, but the totals they produce cluster:
- 2 — 1 way (1+1) — probability 1/36
- 3 — 2 ways — 2/36
- 4 — 3 ways — 3/36
- 5 — 4 ways — 4/36
- 6 — 5 ways — 5/36
- 7 — 6 ways (1+6, 2+5, 3+4, 4+3, 5+2, 6+1) — 6/36
- 8 — 5 ways — 5/36
- 9 — 4 ways — 4/36
- 10 — 3 ways — 3/36
- 11 — 2 ways — 2/36
- 12 — 1 way — 1/36
Seven has the most combinations because it is the only total reachable from every face of the first die. This triangular distribution is why craps and Monopoly behave as they do, and it is a small demonstration of the central limit theorem — sums of independent random variables tend towards a bell shape, even when the individual variables are flat.
Expected values
Expected value of one n-sided die = (n + 1) ÷ 2
A d6 averages 3.5; a d20 averages 10.5.
Expected total of k dice = k × (n + 1) ÷ 2
Two d6 average 7. Three d6 average 10.5.
Note that the expected value of a d6 is 3.5 — a result you can never actually roll. Expected value describes the long-run average, not a typical outcome.
Fairness and the seed
This roller is pseudorandom: the same seed reproduces the same rolls exactly. That is useful for tabletop games where a sequence needs to be verifiable, or for testing a game's mechanics repeatedly under identical conditions.
It also means the roller is unsuitable for anything where an outcome must be genuinely unpredictable and money is at stake. Real gambling systems use certified hardware entropy sources and are independently audited precisely because a predictable generator is exploitable.
Physical dice have their own fairness issues worth noting: cheap injection-moulded dice with hollowed pips are measurably biased, since removing material from the 6 face makes it slightly lighter and the opposite face slightly more likely to land down. Casino dice are precision-machined with flush, density-matched pips for this reason.
Common dice in games
d4, d6, d8, d10, d12, d20 — the standard polyhedral set used in tabletop role-playing games.
2d6 — board games, for the bell-shaped distribution that makes middle values common.
d100 — percentile rolls, usually made with two d10s.
Advantage and disadvantage — rolling two dice and taking the higher or lower. Rolling 2d20 and keeping the highest shifts the average from 10.5 to about 13.8, a substantial change that is far larger than most players estimate.
Common mistakes
Expecting a uniform spread of totals. Only a single die is uniform.
Believing a number is "due". Each roll is independent; the dice have no memory.
Using a seeded roller where unpredictability matters. Reproducibility is the opposite of what you want.
Assuming physical dice are fair. Pipped dice have a measurable bias.
Underestimating advantage. Taking the best of two rolls is worth roughly +3 on a d20.