Parlay Calculator: See the Final Odds and the Compounded Vig
Parlays multiply your winnings but they also multiply the house edge. Three -110 legs each carry about 4.76% hold individually; combined, the parlay hold climbs to roughly 13%. This calculator shows you the final parlay odds, total profit, and payout so you know exactly what you need before building the ticket.
What a parlay costs you beyond the individual legs
A parlay chains multiple bets so all of them must win. The payout is larger than any individual bet, but the probability of collecting drops with every leg added. Each leg that loses kills the entire ticket.
The hidden cost is compounded vig. A single -110 bet carries about 4.76% hold. A 2-leg parlay at -110/-110 runs about 9.1%. A 5-leg parlay climbs to roughly 21%. Sportsbooks make more per dollar risked on parlays than on any other single-bet product, which is why they advertise them so heavily.
Parlays can be +EV when each individual leg is already +EV. In that case, combining them is equivalent to reinvesting winnings between legs. But parlaying -EV legs together compounds the drag without adding any expected return.
How the multiplication works
Convert each American leg to decimal odds. Multiply all decimal odds together. That product is the parlay decimal. Subtract 1 and multiply by stake for profit. Add stake back for total payout.
Three legs at -110 each: decimal 1.909 per leg. Product = 1.909^3 = 6.963. On $100 stake: payout = $696, profit = $596. American equivalent: +596.
The same three legs at fair price (+100 each, decimal 2.00) would give 2.00^3 = 8.00 decimal, payout $800, profit $700. The $104 difference on a $100 bet is compounded vig across three legs.
- 2-leg parlay at -110/-110: combined hold ~9%, American equivalent ~+264 (fair value +300)
- 3-leg parlay at -110/-110/-110: combined hold ~13%, American equivalent ~+596 (fair value +700)
- 5-leg parlay at -110 each: combined hold ~21%, American equivalent ~+2,250 (fair value ~+3,100)
Step by step: using this calculator
Add legs until you have matched your sportsbook ticket exactly. The order of legs does not matter - multiplying decimal odds is commutative.
If the book caps the payout or limits the number of legs, the calculator shows theoretical math only. Accept that limitation and adjust expectations accordingly.
- Enter Parlay Total Wager - what you are risking on the combined ticket.
- Enter Bet #1 Odds through Bet #N Odds for each leg.
- Use the Add leg button to include additional legs.
- Read Parlay Odds, Total Profit, and Total Payout.
Worked example: 3 legs at -110, $100 stake
Parlay Total Wager $100. Three legs at -110 each. Decimal odds per leg: 1.909. Parlay decimal: 1.909 x 1.909 x 1.909 = 6.963. Parlay Odds: +596. Total Payout: $696. Total Profit: $596.
True probability of hitting all three if each is a fair 50-50: 0.50 x 0.50 x 0.50 = 12.5%. At fair +600, break-even win rate is 14.3%. At -110 each leg you get +596 instead of +600, meaning you need 14.4% win rate to break even - essentially the same as fair, but the vig compounds slightly.
Same-game parlays are even more expensive. Sportsbooks apply correlation adjustments that reduce the payout further. SGP holds of 25-40% are not unusual on popular markets.
Combined odds
+596
Profit if win
+$596
Total payout
$696
Parlay compounded hold
Each leg at -110. The taller the bar, the more margin the book takes home.
When parlays make sense
If each leg is independently +EV and you would bet them all separately anyway, combining them into a parlay is mathematically equivalent to reinvesting your winnings between legs. In that narrow case, parlaying is defensible.
Parlaying for entertainment on a small stake is a legitimate reason. Many bettors enjoy the larger potential payout on a small amount. Enter it as a cost of entertainment, not a betting strategy.
The worst version is parlaying correlated same-game props where the book has already priced in the correlation. You do not get the full decimal multiplication - you get a smaller one with similar exposure but higher effective hold.
What most calculator pages skip
OddsGuard replaces paid parlay tools that cost $200 or more per month. The calculator runs locally in your browser, works on any device, and pairs with the extension that shows individual leg prices across 75+ books simultaneously so you find the best price per leg before combining them.