Combine 2–12 legs using the product of decimal odds. See payout and a common per-leg break-even probability under an equal, independent-leg assumption.
If all legs are independent and have the same probability, that common probability must be to break even at this price. Unequal probabilities require their product; correlated legs require a joint probability.
Worked assumption: four independent 50/50 legs, each priced at -110, produce decimal odds of (21/11)⁴ = 13.28. The assumed joint win probability is 6.25%; the offered odds imply 7.53%. Using the unrounded odds product, expected return is 0.0625 × (21/11)⁴ − 1 = −16.98% of stake. This is an example under those assumptions, not a measured bettor win rate.
Read the full math in our parlay math explainer. To explore a stake under your own probability assumption, use the Kelly Criterion calculator.
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Check the odds, joint-probability assumption, and settlement rules before comparing payoffs.