Dice Probability Calculator
Find the odds of rolling a target sum with any dice.
The odds of any roll
Board games and tabletop RPGs hinge on dice odds, and the probability of a given sum is not obvious once you roll several dice. This calculator builds the exact distribution.
Rolling two six-sided dice, a sum of 7 is the most likely at about 16.7%. Enter any number of dice and sides and a target, and it gives the chance of hitting exactly that sum, or at least or at most it.
Exact and private
The calculation runs in your browser, so nothing you enter is uploaded.
Frequently Asked Questions
What does it calculate?
The probability of rolling exactly a target sum, at least it, and at most it, with any number of dice of any sides.
How is it computed?
By building the full distribution of sums through a convolution, so the result is exact.
Can I use non-standard dice?
Yes. Set any number of sides, so d4, d8, d20, and others all work.
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