Dice Probability Calculator
Calculate the probability of various dice roll outcomes with different types of dice and scenarios.
Results
Enter your parameters and click “Calculate Probability” to see results.
Dice Probability Information
Understanding Dice Probability
Dice probability is the mathematical study of the likelihood of getting specific outcomes when rolling dice. For a single fair die, each face has an equal probability of appearing.
For example, with a standard 6-sided die, the probability of rolling any specific number is 1/6 or approximately 16.67%.
When multiple dice are rolled, the probabilities become more complex as we need to consider all possible combinations.
Dice Probability Formulas
Single Die Probability: P(outcome) = 1/n, where n is the number of sides.
Multiple Dice – Exact Sum: The formula involves counting favorable outcomes divided by total possible outcomes.
At Least One Die: P(at least one) = 1 – P(none)
All Dice Equal to Value: P(all equal to x) = (1/n)^d, where d is the number of dice.
Common Examples
Craps Game: In craps, rolling a 7 with two 6-sided dice has a probability of 6/36 = 1/6 = 16.67%.
D&D Checks: In Dungeons & Dragons, rolling 15 or higher on a D20 has a probability of 6/20 = 30%.
Yahtzee: The probability of rolling five of a kind (Yahtzee) on the first roll is 6/7776 = 0.077%.
Two Dice Sum Probability Chart
| Sum | Probability | Odds |
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How to Use the Dice Probability Calculator
Step 1: Select your dice type from the dropdown menu. The calculator supports various dice from 4-sided (D4) to 20-sided (D20), covering most common dice used in games.
Step 2: Enter the number of dice you want to roll simultaneously. You can calculate probabilities for up to 10 dice at once, though calculations become more complex with more dice.
Step 3: Choose your calculation type based on what probability you want to find. Options include exact sum, greater than/less than a value, at least one die showing a specific value, and more.
Step 4: Input your target value based on your calculation type. For sum calculations, this represents the total you’re aiming for. For individual die calculations, it represents the face value you’re interested in.
Step 5: Click the “Calculate Probability” button to see your results. The calculator will display the probability as a percentage and as odds, along with an explanation of how the result was calculated.