Calculate the probability of rolling specific outcomes with various dice combinations. This tool processes all data locally in your browser. No information is ever sent to any server. Completely free, no registration required.
A Dice Probability Calculator computes the likelihood of every possible sum and combination when rolling any number of dice of any size (d4, d6, d8, d10, d12, d20, d100). Essential for tabletop gaming (D&D, Warhammer, board games), game design, and probability education. Rolling 2d6 gives 7 as the most common result (16.7%); rolling 2d12 gives a flat-ish distribution with a plateau. The calculator visualizes the probability distribution as a chart.
Enter the number of dice and their size. The calculator generates the complete probability distribution for the sum: each possible total and its exact probability. For standard 2d6: 2=2.8%, 3=5.6%, 4=8.3%, 5=11.1%, 6=13.9%, 7=16.7%, 8=13.9%, 9=11.1%, 10=8.3%, 11=5.6%, 12=2.8%. The fraction, decimal, and percentage are shown for each sum.
Sum Distribution: P(S) = (number of ways to roll sum S) ÷ (total outcomes = sides^dice)\n\n2d6 (36 outcomes): 7 has 6 combos → 6/36 = 16.7%\n2d20 (400 outcomes): sum range 2-40, bell-shaped\n\nMean = dice × (sides + 1) ÷ 2\nStd Dev = √(dice × (sides² − 1) ÷ 12)
They have similar ranges (2-12 vs. 1-12). 2d6 averages 7 and is more predictable (bell curve). 1d12 averages 6.5 and is more variable (flat). 2d6 is more reliable; 1d12 is more swingy.
1/216 = 0.46%. Only one combination (6+6+6) out of 216 total. For D&D character creation (3d6 for stats), an 18 is a ~1-in-200 roll — that's why it's celebrated.
Free online Dice Probability Calculator — no signup, 100% client-side processing. All data stays in your browser.