Sportsbooks calculate parlay payouts automatically, but knowing how lets you check a price, compare parlays across books and see how much margin you are paying.
Step 1: Convert each leg to decimal
- Positive American: 1 + odds ÷ 100 (+150 → 2.50)
- Negative American: 1 + 100 ÷ |odds| (−150 → 1.667)
Step 2: Multiply the decimals
Three legs: −110 (1.909), +150 (2.50), −200 (1.50)
Step 3: Convert back (optional)
- Decimal ≥ 2: American = (decimal − 1) × 100 → +616
Step 4: Calculate the payout
Total return = stake × parlay decimal. $20 × 7.16 = $143.18 returned ($123.18 profit).
The parlay calculator does all four steps.
Common parlay payouts
| Legs | All at −110 | All at −120 | All at +100 |
|---|---|---|---|
| 2 | +264 | +236 | +300 |
| 3 | +596 | +516 | +700 |
| 4 | +1228 | +1030 | +1500 |
| 5 | +2436 | +1971 | +3100 |
Implied probability of a parlay
1 ÷ parlay decimal. A 7.16 parlay implies 14.0%. If your legs' fair probabilities are 50%, 38% and 64%, the true chance is 0.50 × 0.38 × 0.64 = 12.2%, so the parlay's EV is 0.122 × 7.16 − 1 = −12.9%. (Parlay math.)
What happens with a push?
If one leg pushes (or is voided), most books drop that leg and recalculate the parlay with the remaining legs. A 3-leg parlay with one push becomes a 2-leg parlay. Some books have different rules for same-game parlays; check your book's terms.
Why books' parlay payouts sometimes differ from the math
- Same-game parlays are priced with correlation models, not simple multiplication (SGP correlation)
- Rounding of each leg's decimal
- Parlay boosts or promos
- Maximum payout caps
Shop parlays
Because the payout multiplies each leg's price, getting a slightly better price on every leg compounds. Better to build legs at the books with the best price on each, or compare the full parlay across books. (Line shopping.)
Frequently asked questions
How do you calculate parlay odds?
Convert each leg to decimal odds, multiply them together, and multiply by your stake to get the total return.
How much does a 3-leg parlay pay?
At −110 on every leg, a 3-leg parlay pays about +596, so a $10 bet returns about $69.60.
What happens if one leg of my parlay pushes?
At most books the pushed leg is removed and the parlay pays at the reduced odds of the remaining legs.