Parlay Calculator
Free parlay odds calculator. Add up to 10 legs in American or decimal odds and get combined odds, implied probability, payout, and profit instantly.
How Parlay Odds Work
A parlay multiplies every leg's decimal odds into one combined price, and pays only when every leg wins. That multiplication cuts both ways: payouts grow geometrically, but so does the sportsbook's edge, because each leg carries its own vig. The implied probability shown above is the break-even rate the combined odds demand; compare it honestly against how often all legs really hit together.
Example: three legs at -110, +150, and -105 combine to +832. A $100 stake pays $931.82 total, but the 10.7% implied probability means the books expect this to hit about once in nine or ten tries.
Pricing parlays in an app?
This tool multiplies odds in the browser. Production betting products need the underlying leg prices live from every book, normalized into one schema. That is SharpAPI: real-time odds from 45+ sportsbooks over REST and SSE, with player props and game state for same-game logic. Get a free API key.
Frequently Asked Questions
How are parlay odds calculated?
Convert every leg to decimal odds and multiply them together. Two legs at -110 (1.909) combine to 3.645, about +264. The payout is your stake times the combined decimal odds, and it only pays if every leg wins.
Why do sportsbooks push parlays so hard?
Because the vig compounds. Each leg carries the book margin, so a 4-leg parlay of standard -110 lines carries roughly four times the edge of a straight bet. Parlays are among the highest-hold products a sportsbook offers.
What happens to a parlay if one leg pushes?
At most US books a pushed leg drops out and the parlay reduces to the remaining legs at their combined odds. A 4-leg parlay with one push becomes a 3-leg parlay. Voided legs are usually treated the same way.
What is a same game parlay?
A same game parlay (SGP) combines multiple markets from one event, like a spread plus a player prop. Because outcomes within one game are correlated, books price SGPs with proprietary models rather than simple odds multiplication.
Can a parlay ever be positive EV?
Only if the individual legs are themselves +EV enough to outrun the compounded vig, or when correlated legs are mispriced. Uncorrelated parlays of standard-vig lines are mathematically worse than the same stakes placed as straight bets.
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