Parlay calculator: accumulator payouts up to 12 legs
1win runs 40,000+ daily sports markets under its Curaçao 8048/JAZ licence. This free parlay calculator works out your accumulator payout for up to 12 legs. Mag-register with code XLBONUS to apply your welcome offer to any parlay you build.
Parlay / accumulator calculator
How this calculator works
A parlay (also called an accumulator or acca) combines multiple individual selections into a single bet. All legs must win for the bet to pay out. The combined odds equal the product of each individual leg's decimal odds.
The formula is straightforward: Combined decimal odds = leg1 x leg2 x ... x legN. For example, three legs at 2.00 each produce combined odds of 8.00. A 10-unit stake returns 80 units total, or 70 units net profit.
The calculator accepts decimal, American, and fractional input. American odds are converted internally: positive odds use (n/100 + 1) and negative odds use (100/|n| + 1). Fractional odds convert via (numerator/denominator) + 1.
Each leg also carries a win/lose selector. A single losing leg collapses the parlay payout to zero (unless the leg is voided, which removes it from the calculation). Voided legs use a decimal of 1.00 (no change to combined odds).
The implied probability column shows the raw probability of all legs winning simultaneously: 1 / combined decimal. A 5-leg parlay at average odds of 1.90 per leg gives combined odds of roughly 24.76 and an implied probability around 4%. This figure does not account for bookmaker margin, so the true probability will be even lower.
Maximum 12 legs are supported. This matches common sportsbook limits and keeps the combined odds display readable. At 1win you can build parlays across multiple sports in a single bet slip, mixing football, tennis, basketball, and more.
A common mistake is forgetting that each additional leg multiplies risk, not just reward. Even adding one 1.50-priced "banker" to a parlay means that selection must also win. The probability of all legs winning falls dramatically with each addition.
Why use it at 1win
1win's parlay builder covers 40,000+ markets. Build your accumulator, then use code XLBONUS when you register to receive your welcome bonus on top of any parlay winnings.
FAQ
How many legs can a parlay have?
This calculator supports up to 12 legs. Most sportsbooks, including 1win, allow at least 12-15 selections in a single accumulator. The minimum is 2 legs.
What happens if one leg is void?
If a selection is voided (cancelled by the bookmaker), that leg is treated as a 1.00 decimal and removed from the combined odds. The parlay pays out on the remaining legs.
Are parlay odds better value than single bets?
Parlays offer higher potential payouts but lower expected value because the bookmaker's margin compounds across every leg. Singles generally have better expected value for skilled bettors.
How do I enter American odds?
Select "American" from the format dropdown, then enter positive values for underdogs (e.g. +150) and negative values for favorites (e.g. -110). The calculator converts to decimal internally.
What is a "same-game parlay"?
A same-game parlay combines multiple outcomes from a single match. The legs are correlated, so true odds differ from a standard parlay. This calculator models each leg as independent.