Dice Roller
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History
Your results will appear here. Tap Use on any of them to carry it into the next calculation, in this calculator or another one. History is kept while this tab is open.
To roll dice online, choose how many dice and which die, d4 to d100, then press Roll. The online dice roller shows each die and the total. One d6 is set by default, so to roll a die you only need to press Roll once.
Roll a six-sided die
The page opens with Dice 1 and Die d6, the ordinary six-sided die. Press Roll and you get a number from 1 to 6. Each face has the same chance: 1 ÷ 6, or 16.67%.
There's nothing to set up for 6-sided dice. Every press of Roll is a new dice roll, so press it again whenever you need the next number.
Dice types: d4, d6, d8, d10, d12, d20, d100
Polyhedral dice are named by their faces. dN is a die with N faces, numbered 1 to N: a d4 has four, a d20 has twenty. On this page, the 10-sided die gives 1 to 10 and the d100 gives 1 to 100.
A number in front counts the dice. 2d6 means two six-sided dice: 2 is how many, d6 is the type.
Each face of a d4 comes up 25% of the time, of a d20 5%, of a d100 1%. To roll d20, pick d20 on the Die switch and press Roll. d4 dice, d12 dice and d100 dice work the same way.
Rolling two or more dice
To roll two dice, enter 2 in Dice and press Roll. For 2d6 that's Dice 2 and Die d6; for 3 dice, enter 3. One roll takes up to 100 dice, all of the same type.
The total appears in large type. Below it you see each die in the order it came up: for example 9, with 4 + 5 underneath. With more than 10 dice, the row of values scrolls inside the display.
Rolling several times and want the average total? Send each total to the average calculator with Use. It adds the number to the end of its list.
How the dice are rolled
In this virtual dice roller, every face has the same chance of coming up:
chance of each face = 1 ÷ N
N is the number of faces: a d20 gives 1 ÷ 20, or 5%.
The numbers come from your browser's cryptographic generator, crypto.getRandomValues in the Web Crypto API. So this is a dice simulator built on a pseudo-random number generator: an algorithm produces the numbers, and no physical die is thrown. To fit them to the range 1 to N without favoring any face, the roller discards values that would skew the result and draws again. The dice in one roll are independent of each other.
It all happens in your browser, and the numbers are not sent anywhere. Need a number from your own range instead of 1 to N? Use the random number generator.
Dice probability
There's no probability mode on the page, but the math is short. The average total of n dice with N faces is:
average total = n × (N + 1) ÷ 2
One d6 averages 3.5 and two d6 average 7. For 3 × d6 it's 10.5, for one d100 it's 50.5, and for 100 × d100 it's 5 050.
Why is 7 the most common total with two d6? The pair can land in 36 combinations, and six of them add up to 7. That's 6 ÷ 36, about 16.67%. Totals 2 and 12 have one combination each, about 2.78%.
To see it on your own rolls, roll 2 × d6 a few times and send the totals to the average calculator.
Examples
Every roll is different, so each row shows what always holds: the range of the total and its average.
| You roll | Total | Average total | On the display |
|---|---|---|---|
| 1 × d6 | 1 to 6 | 3.5 | One number, no row of values |
| 2 × d6 | 2 to 12 | 7 | For example 9, with 4 + 5 below |
| 1 × d20 | 1 to 20 | 10.5 | One number, no row of values |
FAQ
How do I roll a die online?
Dice 1 and Die d6 are already set, so just press Roll. For another die, pick it on the Die switch first.
What does d20 mean?
A die with 20 faces, numbered 1 to 20, each with a 5% chance. Pick d20 on the Die switch and press Roll.
Can I roll more than one die at once?
Yes, up to 100 dice of one type: enter the number in Dice. You see each die and the total. Enter 101 or more and you get the error Use 1–100.
Is the virtual dice roller random?
It uses the cryptographic pseudo-random number generator built into your browser, and every face is equally likely. That's enough for games and lessons. It's still an algorithm, not a physical die.
What is the most common total with two dice?
7: six of the 36 combinations add up to it, about 16.67%. Totals 2 and 12 have one combination each, about 2.78%.