Calculate the probability of rolling specific totals with multiple dice. Supports D4 through D20 with visual distribution charts.
What Is Dice Probability Calculator?
Dice probability calculation determines the likelihood of rolling specific outcomes with one or more dice. While a single six-sided die has uniform probability (1/6 for each face), rolling multiple dice creates a bell-curve distribution where middle values are far more likely than extremes. For example, rolling 2d6 produces 7 as the most common sum (6 out of 36 combinations) while 2 and 12 each have only a 1-in-36 chance.
Understanding dice probabilities is valuable for tabletop gaming, probability education and statistical intuition. This tool calculates exact probabilities for any combination of dice, showing the likelihood of each possible sum and the probability of rolling above, below or equal to a target number.
How to Use This Tool
Select the number of dice to roll (up to 3 free, up to 6 with Premium).
Choose the type of dice — d4, d6 and d8 are free; d10, d12 and d20 need Premium.
Enter a target sum, then click "Calculate Probabilities".
See the exact, at-least and at-most probability for your target plus the average roll.
The chart below visualises the full distribution — which sums are most and least likely.
Tips & Best Practices
The probability of rolling a specific total on 2d6 is not uniform — 7 is six times more likely than 2 or 12.
Adding more dice makes extreme results increasingly unlikely and concentrates probability around the average.
The average roll for any fair die is (minimum + maximum) / 2 — for a d6, that is 3.5.
In games like Dungeons & Dragons, rolling with "advantage" (best of two d20s) raises your average from 10.5 to 13.8.
Common Use Cases
Calculating optimal strategies in tabletop RPGs and board games.
Teaching probability and statistics with tangible, relatable examples.
Evaluating the likelihood of specific outcomes in dice-based games.
Simulating probability distributions for maths or statistics courses.
Frequently Asked Questions
What dice types are supported?
Free users can calculate for D4, D6, and D8 with up to 3 dice. Premium adds D10, D12, D20 with up to 6 dice.