Free Tool
Parlay Calculator
Build your parlay and see the real probability math. Add selections, enter odds, and discover your true chances.
Parlays require ALL selections to hit, which dramatically reduces the overall probability. Here is the math:
- Individual probabilities multiply: A 60% outcome + 70% outcome = 42% combined (0.6 x 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
- Market odds usually pay less: Compare offered odds to our "fair odds" calculation
Use this tool to understand the real math behind parlays before committing.
How do parlay odds work?
Parlay odds multiply together because ALL legs must win. If you have two 50% probability outcomes, the combined probability is 50% x 50% = 25%. Each additional leg dramatically reduces the overall chance.
Why are parlays risky?
Parlays typically offer lower payouts than the true mathematical odds would suggest. The vig increases on parlays, making them less favorable than betting each selection individually.
What is the difference between fair odds and market odds?
Fair odds represent what the parlay should pay based on pure mathematics. Market odds are usually lower because they include the vig on top of the already difficult combined probability.
How many legs should I include?
Mathematically, fewer legs are better. Each additional leg multiplies the difficulty. Most experienced bettors limit parlays to 2-3 legs maximum.
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