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Parlay Calculator
Parlay Calculator
Enter your legs and stake. You get the payout, the combined odds, how often a parlay like this actually hits, and the part every sportsbook hides: how much juice you are paying.
How parlay odds are calculated
A parlay multiplies the decimal odds of every leg. That is the whole formula. The sportsbook first converts each American price to decimal odds, multiplies them together, then multiplies by your stake.
- Negative odds (favorite): decimal = 1 + 100 ÷ |odds|. So -110 = 1.909, -200 = 1.50.
- Positive odds (underdog): decimal = 1 + odds ÷ 100. So +150 = 2.50, +300 = 4.00.
Payout = stake × (decimal₁ × decimal₂ × … × decimalₙ)
Because it is a product, one leg at -300 barely moves the payout while one leg at +400 quadruples it. That is why books love pushing heavy favorites into parlays: they add risk to your ticket without adding much to your return.
A worked example
Three legs, $20 stake: Chiefs -110, Lakers +150, Yankees -140.
| Leg | American | Decimal | Implied prob. |
|---|---|---|---|
| Chiefs spread | -110 | 1.909 | 52.4% |
| Lakers moneyline | +150 | 2.500 | 40.0% |
| Yankees moneyline | -140 | 1.714 | 58.3% |
| Parlay | +718 | 8.18 | 12.2% |
$20 × 8.18 = $163.60 payout, $143.60 profit. The implied probability of 12.2% means you need this ticket to hit more than once every 8.2 tries just to break even. Since each leg carries the book's margin, the true probability is closer to 10.6%, which is why the calculator shows a house edge of about 13% on this ticket.
Why the house edge explodes with each leg
On a single -110 bet, the book's edge is about 4.5%. A parlay compounds that margin: every leg you add multiplies the juice in. Here is what a parlay of standard -110 legs really pays against what a fair book would pay.
| Legs | Book pays | Fair odds | True hit rate | House edge |
|---|---|---|---|---|
| 2 | +264 | +300 | 25.0% | 8.9% |
| 3 | +596 | +700 | 12.5% | 13.0% |
| 4 | +1228 | +1500 | 6.25% | 17.0% |
| 5 | +2436 | +3100 | 3.1% | 20.8% |
| 6 | +4741 | +6300 | 1.6% | 24.4% |
| 8 | +17545 | +25500 | 0.39% | 31.1% |
| 10 | +64208 | +102300 | 0.10% | 37.2% |
| 12 | +234279 | +409500 | 0.02% | 42.8% |
Same-game parlays and correlation
A same-game parlay (SGP) bundles bets from one game: a quarterback's passing yards, his top receiver's yards, and the over. These legs are correlated: if the QB throws for 350, the receiver and the over probably hit too. Multiplying the odds as if they were independent would overpay you, so books quietly price SGPs with a correlation adjustment. The displayed odds are lower than the plain product, and the hold on SGPs is typically 20–30% even at two or three legs.
Correlation is not always bad for you. Books adjust for the obvious links (QB + WR) and sometimes miss the subtle ones (a heavy underdog moneyline + the under in a game expected to be a slow grind). Finding under-priced correlation is one of the few ways to get real value from a parlay, and it is the same logic we apply when we build our own picks.
When a parlay actually makes sense
- Every leg is +EV on its own. If each leg beats the closing line, the parlay compounds your edge just like it compounds the juice. Use our EV calculator to check each leg first.
- Promotions. "Parlay insurance", profit boosts and no-sweat parlays change the math. A 30% boost on a 3-leg -110 parlay turns a 13% house edge into a small edge for you.
- Bankroll constraints. If you only want to risk $5 on a 1-in-20 shot for entertainment, a parlay is a cheap lottery ticket. Just size it like one.
Outside those cases, splitting the same stake into single bets keeps the house edge at 4–5% instead of 15–40%.
Parlay vs. round robin vs. singles
With four legs and $40 to bet, here are your three options:
| Structure | What you bet | If 3 of 4 hit | If 4 of 4 hit | House edge |
|---|---|---|---|---|
| 4 singles ($10 each, -110) | $40 | +$17.27 | +$36.36 | 4.5% |
| Round robin (six 2-leg parlays, $6.67 each) | $40 | +$32.90 | +$105.80 | 8.9% |
| 4-leg parlay | $40 | −$40 | +$491.20 | 17.0% |
A round robin sits in the middle: it still pays when one leg fails, at a lower hold than the full parlay. Most professional bettors use singles for their core volume and reserve parlays for correlated spots or promos.
FAQ
What happens if one leg pushes?
At almost every US and Canadian book, a pushed leg is removed and the parlay pays as if it had one fewer leg. A 4-leg with one push becomes a 3-leg. Some "SGP" products void the whole ticket instead; check the house rules.
Does the order of the legs matter?
No. Multiplication is commutative, so the payout is the same whatever the order.
Can I mix sports in one parlay?
Yes, at any regulated book in the US or Canada. Cross-sport parlays are actually a good way to avoid hidden correlation the book prices against you.
How does the calculator estimate the "fair" probability?
If you enter the other side of each line, it removes the vig exactly (multiplicative method). If you do not, it assumes each leg carries the same margin as a standard -110/-110 market, about 4.5%. Real margins vary: moneylines on big favorites and player props usually carry more.
Is a 2-leg parlay ever a good idea?
It is the least bad parlay: 8.9% hold at -110, and often subsidized by promos. Still worse than two singles unless the legs are correlated in your favor.
Stop guessing which legs are worth it
Elite Bettings publishes NFL, NBA, MLB and NHL picks with a track record you can verify on a third-party tracker. Every pick comes with the fair odds and the edge we see. Try it before your next ticket.
See today's picks21+ in most US states (18+ in DC, NH, RI, WY), 19+ in most Canadian provinces (18+ in AB, MB, QC). This calculator is for information only and does not guarantee results. Gambling problem? Call 1-800-GAMBLER (US) or 1-866-531-2600 (ConnexOntario). Odds shown are examples and change constantly.