Parlay Probability Builder
Build your parlay and see the real probability math. Add legs, enter odds, and discover your true chances of winning.
Parlays require ALL legs to win, which dramatically reduces your chances of success. Here's the math:
- Individual probabilities multiply: A 60% bet + 70% bet = 42% parlay (0.6 × 0.7)
- More legs = lower probability: Each additional leg multiplies the difficulty
- Fair odds reflect true probability: What the parlay should pay in a fair market
- Sportsbook odds usually pay less: Compare their odds to our "fair odds" calculation
Use this tool to understand the real math behind your parlay before placing the bet.
How do parlay odds work?
Parlay odds multiply together because ALL legs must win. If you have two 50% probability bets, the parlay probability is 50% × 50% = 25%. Each additional leg dramatically reduces your chances of winning.
Why are parlays considered bad bets?
Parlays typically offer lower payouts than the true mathematical odds would suggest. The sportsbook increases their edge on parlays, making them less favorable than betting each leg individually.
What's the difference between fair odds and sportsbook odds?
Fair odds represent what the parlay should pay based on pure mathematics. Sportsbook odds are usually lower because they include the house edge (vig) on top of the already difficult parlay probability.
How many legs should I include in a parlay?
Mathematically, fewer legs are better. Each additional leg multiplies the difficulty. Most professional bettors avoid parlays entirely or limit them to 2-3 legs maximum for entertainment purposes.