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Enter each leg's odds to get the parlay price and payout. Add the fair (no-vig) odds per leg and you'll also see what the ticket is really worth. That's the part no other parlay calculator shows you.
Add fair odds on every leg to see the no-vig parlay price and the vig you're actually paying.
A parlay multiplies the decimal odds of every leg. Two legs at −110 (decimal 1.909) combine to 1.909 × 1.909 = 3.645, which is +264. Your payout grows fast. So does something else:
Every leg multiplies the vig, too. A single −110/−110 market carries about 4.5% of book margin. Stack legs and the tax compounds:
| Legs (each −110) | Parlay odds | Vig you're paying |
|---|---|---|
| 1 | −110 | ~4.5% |
| 2 | +264 | ~8.9% |
| 3 | +596 | ~13.0% |
| 4 | +1228 | ~16.9% |
That's the whole reason sportsbooks market parlays so hard. It's also the reason the fair-odds column exists on this calculator. Fill it in and the tool shows the no-vig price of your exact ticket and the EV you're giving up (or, with a boost applied, gaining).
One honest caveat: multiplying legs assumes they're independent. Same-game parlay legs are correlated, which is why books reprice SGPs internally. For SGPs, treat this calculator's fair math as an approximation, not gospel.
Because vig compounds per leg. A bettor grinding single −110 bets pays ~4.5% margin; the same bettor on 4-leg parlays pays ~17%. Parlays are the book's highest-margin product, dressed up as a lottery ticket.
For the price and payout, yes. For the fair-value math, carefully: SGP legs are correlated (a QB's passing yards and his team winning move together), so multiplying independent fair probabilities overstates or understates the truth depending on the combo. Books know this and reprice SGPs internally.
The product of each leg's no-vig win probability, converted back to odds. If two legs are each a fair 50% (+100 no-vig), the fair parlay is 25%, which is +300. Anything less than +300 on that ticket is vig. This calculator does exactly that math in the fair column.
Got a profit boost to put on a slip? Price it properly first. That's what the desk does every morning.