Craps Odds Calculator
Every craps bet rests on the fixed combinatorics of two dice: 36 equally likely outcomes with a known number of ways to make each total. Enter a target total from 2 to 12 and the payout to one for a winning one-roll bet on it. The calculator returns the number of ways to roll that total, the exact probability, the expected value per unit staked, and the house edge as a percentage. The probabilities never change because they come from the geometry of the dice, so the only thing the casino can adjust is the payout, which sets the edge.
Craps dice formulas
Ways(total) = 6 - |total - 7| for totals 2 to 12
Win probability p = Ways / 36
Expected value = p * payout - (1 - p) * 1
House edge percent = -Expected value * 100
The number of ways to roll a total rises linearly from 1 at the extremes to 6 at a total of 7. Dividing by the 36 equally likely outcomes gives the exact probability of that total on a single roll.
Ways to make each total
- 2 and 12: 1 way each, probability 1/36, about 2.78 percent.
- 3 and 11: 2 ways each, probability 2/36, about 5.56 percent.
- 4 and 10: 3 ways each, probability 3/36, about 8.33 percent.
- 5 and 9: 4 ways; 6 and 8: 5 ways; 7: 6 ways (the most common).
- The eleven totals from 2 to 12 sum to 36 ways, covering every outcome.
Craps odds: frequently asked questions
How are two-dice probabilities calculated?
Two fair six-sided dice produce 36 equally likely ordered outcomes. The number of ways to make each total is fixed: one way for 2 or 12, two for 3 or 11, and so on up to six ways for 7. The probability of a total is its number of ways divided by 36. This is exact combinatorics.
Why is 7 the most common roll?
A total of 7 can be made six ways (1-6, 2-5, 3-4 and their reverses), more than any other total, so its probability is 6/36, about 16.67 percent. This is why 7 is central to craps and why the come-out and point rules revolve around it.
What does this calculator compute for a bet?
For a one-roll bet on a chosen total, it gives the probability of winning, the expected value per unit staked using the payout to one you enter, and the house edge as a percentage. Expected value is the win probability times the payout minus the lose probability times 1.
What is the house edge on common craps bets?
The pass line bet has a house edge of about 1.41 percent over the full sequence of rolls. One-roll proposition bets such as any 7 or the hard ways carry much higher edges. This calculator computes the edge of a single-roll bet from the total and payout you supply.
What inputs does this calculator take?
Enter the target total from 2 to 12 and the payout to one for a winning one-roll bet on that total. The probability comes from the fixed dice combinatorics, and the expected value and house edge follow from your payout.
Official sources
- Nevada Gaming Control Board: Gaming regulations and approved game rules.
- NIST/SEMATECH e-Handbook of Statistical Methods: Probability and expected value.
Reviewed by the CalculatorHub team, edited by James Graham, 16 June 2026. See our methodology.