How dice probabilities work
With one die every face is equally likely, but as soon as you add dice the sums bunch up in the middle. There are more ways to roll a 7 with two dice than a 2 or a 12, because 7 can come from 1+6, 2+5, 3+4 and their reverses. This tool counts every combination exactly.
Exact counting, not guessing
The calculator builds the full distribution of sums by convolution — effectively listing every possible outcome — so the probability is precise, not a simulation. It shows the number of favourable outcomes, the total, and the odds as "1 in N".
Board games and tabletop RPGs
Handy for checking your odds in Monopoly, Catan or Dungeons & Dragons, where non-standard dice like d20 or multiple d6 are common. Change the number of sides to model any die from a d4 to a d100.
Frequently asked questions
What are the odds of rolling a 7 with two dice?
Six of the 36 equally likely outcomes total 7, so about 16.7%, or 1 in 6.
Can it handle 20-sided dice?
Yes. Set the sides to 20 for a d20, or any value up to 100, with as many dice as you like.
How do I calculate dice probabilities?
Divide the number of ways an outcome can happen by the total number of outcomes. With two dice there are 36 combinations, so a total of 7 (six ways) has a 6/36 = 1 in 6 chance.
Why is 7 the most common roll with two dice?
Because more combinations add to 7 than to any other total. Extreme totals like 2 or 12 have only one combination each, so they're the rarest.
How does adding more dice change the odds?
The totals cluster more tightly around the middle. With many dice, middle sums become far more likely and the extremes become very rare.