⚂ Dice Probability Calculator
Calculate roll probabilities, view full distributions, simulate rolls, and compare D&D 5e advantage vs disadvantage.
Configure Your Roll
dice
mod
total
—
How Dice Probability Works
For a single die, every face has equal probability (1/faces). For multiple dice, the distribution follows a convolution — the bell-curve shape gets more pronounced as you add more dice. This is why 2d6 averages 7 and extreme results (2 or 12) are far less likely than middle values.
Advantage in D&D 5e means rolling two d20s and keeping the higher result. The probability of getting at least X with advantage is: 1 − P(both rolls below X)² = 1 − ((X−1)/20)².