Dice Probability Calculator
Choose how many dice to roll and how many sides they have, and see the exact chance of every total. You can keep only the highest or lowest dice, which covers advantage and disadvantage on a d20 and rolling 4d6 and dropping the lowest, and add a modifier. Enter a target to get the chance of rolling at least, at most or exactly that number, and press the button to roll the dice once. Everything runs in your browser.
Rolling 2d6
| Total | Exactly | At least | At most | Chance |
|---|---|---|---|---|
| 2 | 2.78% | 100.00% | 2.78% | |
| 3 | 5.56% | 97.22% | 8.33% | |
| 4 | 8.33% | 91.67% | 16.67% | |
| 5 | 11.11% | 83.33% | 27.78% | |
| 6 | 13.89% | 72.22% | 41.67% | |
| 7 | 16.67% | 58.33% | 58.33% | |
| 8 | 13.89% | 41.67% | 72.22% | |
| 9 | 11.11% | 27.78% | 83.33% | |
| 10 | 8.33% | 16.67% | 91.67% | |
| 11 | 5.56% | 8.33% | 97.22% | |
| 12 | 2.78% | 2.78% | 100.00% |
The odds are exact, not simulated. For a plain sum the calculator combines the dice one at a time. For keep highest or keep lowest (advantage, disadvantage, or rolling 4d6 and dropping the lowest) it counts every way the faces can fall and keeps only the dice that count. Dice notation works too: 4d6kh3 keeps the highest 3, 2d20kl1 keeps the lowest 1, and 3d8+2 adds 2. The roll button uses your browser's secure random generator. Up to 20 dice with up to 100 sides each. Everything is worked out in your browser.
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Math & MoneyAbout the Dice Probability Calculator
The odds are exact, not simulated. For a plain sum the calculator combines the dice one at a time, and for keep highest or keep lowest rules it counts every way the faces can fall, weighting each by the multinomial coefficient, and keeps only the dice that count. Two six sided dice give a total of 7 with probability 6 in 36, or 16.67%, the most likely total, and the average of N dice with S sides is N times (S plus 1) over 2, with variance N times (S squared minus 1) over 12. Rolling a d20 with advantage, two dice keeping the higher, has an average of 13.825 against 10.5 for a single d20, a 9.75% chance of a natural 20 against 5%, and a 75% chance of 11 or more against 50%. Disadvantage, keeping the lower of two, averages 7.175 and gives a 0.25% chance of a 20. Rolling 4d6 and dropping the lowest, a popular way to generate ability scores, averages 12.24 with totals from 3 to 18. Dice notation is understood: 4d6kh3 keeps the highest 3, 2d20kl1 keeps the lowest 1, and 3d8+2 adds 2. The roll button uses your browser's secure random generator. The limit is 20 dice with up to 100 sides each.
What are the odds of rolling a 7 with two dice?▾
6 in 36, which is 16.67%. Seven is the most likely total of two six sided dice because there are six ways to make it: 1 and 6, 2 and 5, 3 and 4, and the three reversed pairs.
How much does advantage help on a d20?▾
Rolling two d20 and keeping the higher raises the average from 10.5 to 13.825. The chance of rolling 11 or more rises from 50% to 75%, and the chance of a 20 from 5% to 9.75%. Disadvantage does the reverse.
What does 4d6 drop lowest mean?▾
Roll four six sided dice, discard the lowest, and add the other three. The total ranges from 3 to 18 and averages about 12.24, higher than the 10.5 of plain 3d6. In the calculator it is 4d6 with keep highest set to 3.
How do I read dice notation like 2d6+3?▾
The first number is how many dice, the number after d is how many sides each has, and the number after the plus or minus is a modifier added to the total. So 2d6+3 means roll two six sided dice and add 3.
Is my data uploaded?▾
No. The odds are worked out in your browser and nothing you enter is sent anywhere.