Get the exact probability of any dice total — exact, at-least and at-most odds for NdS, counted exactly, not simulated.
This is about odds, not rolling: for actually rolling dice, use the Dice Roller. Here you get the exact probability of a total before you roll.
Exact probabilities are counted over all possible rolls — no simulation, no rounding of the odds themselves.
chance of the exact total
How to use this tool
Type how many dice you are rolling (1 to 20) and pick the die type: d4, d6, d8, d10, d12, d20 or d100.
Type the total you are aiming for. Totals outside the possible range are allowed — they correctly report a 0% exact chance.
Read the exact chance first, then the ways (for example 6 of 36 rolls), the at-least and at-most chances, the average total, and the possible range.
Compare targets: middle totals beat extremes by a wide margin, so a target near the average is a much safer bet than one near an edge.
Formula & worked example
Rolling 2d6 and wanting a total of 7: six combinations make 7 (1+6, 2+5, 3+4, 4+3, 5+2, 6+1) out of 36 possible rolls, so the exact chance is 16.67%. The chance of at least 7 is 58.33% (21 of 36 rolls), and the average total is 7.
Limitations — read this before you rely on it
Probabilities assume perfectly fair dice with every face equally likely; real dice can be slightly biased, and this tool cannot detect that. Counts are exact, but results are capped at 20 dice and 100 sides to keep the counting fast in the browser — larger pools need statistical approximation instead. Probabilities describe a single fresh set of rolls; they do not predict streaks, and past rolls never change the odds of the next roll.
Frequently asked questions
Every roll of fair dice is equally likely, so probability is just counting: ways to reach the total divided by all possible rolls. For 2d6 there are 36 rolls; six of them total 7, so the chance is 6 ÷ 36 = 16.67%. This calculator counts exactly, by building the full distribution die by die.
Middle totals, because more combinations make them. With 2d6, 7 has six combinations but 2 and 12 have only one each, so 7 is six times as likely as 2. The same bell shape appears with any number of dice.
“At least” counts every total from the target upward; “at most” counts every total from the target downward. Both include the target itself, so for 2d6 and target 7: at least 7 is 58.33% and at most 7 is also 58.33% (the two overlap at exactly 7).
No — dice have no memory. After ten rolls without a 7, the next roll is still 16.67% to be 7. The probabilities here describe a single fresh set of rolls, not streaks.
Use the Dice Roller when you want an actual random result. Use this calculator when you want to know the odds before rolling — for example, whether a target number in a board game is a gamble or a safe bet.