Parlay Probability Calculator
Enter each leg's chance of winning as a percentage, then add or remove legs. We multiply them to get the estimated combined chance the whole ticket cashes.
Independence assumption: This calculation assumes all selections are independent. Correlated legs — such as two selections from the same game — can produce materially different results.
Estimated combined probability16.50%
Roughly 1 in6.1
Estimated fair decimal odds6.061
Estimated fair American odds+506
Example
Three legs at 55%, 50% and 60% multiply to 0.55 × 0.50 × 0.60 = 16.5%.
That is roughly 1 in 6, and it corresponds to estimated fair odds of about +506. If the book pays less than that, the price is working against you.
What the results mean
- Estimated combined probability
- Every leg's chance multiplied together, assuming the legs are independent.
- Roughly 1 in
- The same number expressed as a frequency, which is often easier to feel.
- Estimated fair odds
- The price that combined chance corresponds to with no sportsbook margin added.
Frequently asked questions
Keep reading
- How parlay probability works — why multiplying legs gets harsh fast
- Parlay correlation explained — when multiplying probabilities breaks down
- Why same-game parlays are different — books price correlation their own way
Need correlation checks and market-based fair pricing?
No picks. No locks. No hype. Just the math.