A parlay of three legs at -110 apiece multiplies its odds together, which is why $100 grows into $695.79 instead of a modest bump. That same multiplication compounds the book’s edge, since every leg still carries its own hold, and the size of the number on a ticket doesn’t tell a bettor what’s really baked into it.
Enter a stake and the odds for each leg to see the parlay’s payout, its converted American and decimal odds, and the implied probability of the whole ticket hitting. That last number matters more than the payout, since it shows the real price a bettor pays to stack legs into one bet.
What a $100 parlay wins with every leg at -110, and in brackets what it would win with no vig if each leg were a true coin flip. The gap is the book’s edge, and it grows with every leg: on a 12-leg parlay the price pays a little over half of the fair amount.
| 2 legs | $264 (fair $300) |
|---|---|
| 3 legs | $596 (fair $700) |
| 4 legs | $1,228 (fair $1,500) |
| 5 legs | $2,436 (fair $3,100) |
| 6 legs | $4,741 (fair $6,300) |
| 7 legs | $9,142 (fair $12,700) |
| 8 legs | $17,545 (fair $25,500) |
| 9 legs | $33,585 (fair $51,100) |
| 10 legs | $64,208 (fair $102,300) |
| 11 legs | $122,670 (fair $204,700) |
| 12 legs | $234,279 (fair $409,500) |
| 13 legs | $447,351 (fair $819,100) |
| 14 legs | $854,126 (fair $1,638,300) |
| 15 legs | $1,630,694 (fair $3,276,700) |
Start with the stake, then add each leg, from two up to fifteen. Enter the odds for every leg as posted at the book, whether that’s a number like -110 or +150.
The result shows the parlay’s odds in American and decimal form, the profit on the stake, the total payout, and the implied probability of the whole ticket hitting. Read the implied probability first, since it shows how often a parlay like this actually cashes, not just what it pays when it does.
The calculator converts each leg’s odds to decimal form, then multiplies every leg’s decimal odds together into one combined number. The payout is the stake times that number, which is why parlay payouts climb faster than a straight bet ever would. The implied probability of the whole parlay is the product of each leg’s own implied probability, and since each leg’s number already carries the hold, the true chance of hitting is a bit better than what’s shown.
With a $100 stake across three legs of -110, the combined odds work out to +596, or 6.958 in decimal form. That multiplies out to a $695.79 payout, a profit of $595.79 on the original stake. The implied probability of hitting all three legs comes to 14.4%, lower than any one leg’s own number because three probabilities under 100% get multiplied together.
Parlays make the most sense when every leg is one a bettor already likes on its own, not when a weak pick gets stacked onto a strong one just to inflate the payout. The common mistake is judging the bet by the number on the ticket instead of the implied probability underneath it. A ticket paying +596 looks generous, but a 14.4% implied probability means it misses far more often than it lands.
Every added leg multiplies the hold at the same rate it multiplies the payout, since each leg brings its own vig along for the ride. A sharp bettor treats the implied probability as the real price of the parlay, weighs it against betting each leg straight, and keeps the number of legs low instead of stretching to the maximum just to chase a bigger payout.
What happens if one leg of a parlay loses? The whole ticket loses. A parlay only pays when every leg wins, so there’s no partial credit for winning two out of three.
Does adding another leg always raise the payout? Yes, since multiplying by another leg’s odds greater than 1 always increases the total, but it also lowers the implied probability of the whole ticket cashing.
How is implied probability different from the odds shown on the ticket? The odds show what a winning ticket pays, while implied probability shows the real chance the book has priced into it, hold included, which is usually lower than it looks.