How to Calculate NBA Parlay Odds Step by Step
Converting American odds to decimal, then multiplying the legs together — that's all parlay math is. Once you've done it twice, it sticks for life.
Why You Need to Know How Parlay Odds Work
I spent years at the track trusting the tote board without checking the math myself. Bad habit. The same trap trips up new sports bettors who just slide legs onto a slip and hope for the best. Knowing exactly what a three-leg NBA parlay returns on $10 before you confirm it changes how you shop lines and pick legs.
Step 1 — Convert Each Leg to Decimal Odds
Every calculation starts here. Two simple formulas cover all American odds:
- Negative odds (e.g., -110): (100 ÷ 110) + 1 = 1.91
- Positive odds (e.g., +120): (120 ÷ 100) + 1 = 2.20
Standard NBA spread and total bets price at -110, which converts to 1.91 in decimal. That's your baseline for almost every leg you'll add.
Step 2 — Multiply All the Decimal Odds Together
Take your decimal figures and chain-multiply them. Three legs at -110 each:
1.91 × 1.91 × 1.91 ≈ 6.96
That combined multiplier is your parlay decimal. A $10 stake × 6.96 = $69.60 total return (about $59.60 profit). Not bad for three correct picks — but every single one has to land.
How Odds Shift the Payout Fast
Swap one -110 leg for a +120 underdog (decimal 2.20) and the chain becomes 1.91 × 1.91 × 2.20 ≈ 8.02. That same $10 now returns roughly $80.20. One underdog leg adds more than ten dollars to a ten-dollar bet. That dynamic is why NBA parlay strategy around leg count and odds selection matters so much.
| Parlay Setup | Decimal Multiplier | $10 Total Return | $10 Profit |
|---|---|---|---|
| 3 legs × -110 | ≈ 6.96 | ≈ $69.60 | ≈ $59.60 |
| 2 legs × -110, 1 leg × +120 | ≈ 8.02 | ≈ $80.20 | ≈ $70.20 |
| 2 legs × -110, 1 leg × +150 | ≈ 9.20 | ≈ $92.00 | ≈ $82.00 |
What Happens When a Leg Pushes?
A push means that leg ties — no win, no loss. The sportsbook removes it from the parlay and recalculates using the remaining legs' decimal odds. Your three-leg parlay becomes a two-legger. Payouts drop, but the bet survives. Full definition in the NBA parlay betting glossary.
Same-Game Parlays and the Math Behind Big Numbers
The same multiplication rule applies to same-game parlays, but sportsbooks may apply a correlation discount to legs that are statistically linked. That's why an SGP's displayed odds sometimes look lower than raw multiplication would suggest. The mechanics of picking compatible legs are covered in the guide to building an NBA same-game parlay.
The Vig Is Always in the Math
Standard -110 pricing reflects the sportsbook's built-in commission (vig). A true 50/50 outcome would pay +100 (decimal 2.00); -110 pays less. Over a long parlay card that gap compounds fast. When you're comparing books, even a half-point of juice difference on each leg can meaningfully shift your multiplier — check which sportsbooks offer the best NBA parlay odds to see where lines tend to be sharpest.
Run this calculation before every parlay, not after. Know what you're expecting to win before you confirm the slip. Must be 21+ (18+ in select states). Gambling problem? Call 1-800-GAMBLER.
For more on today's odds boosts that can push those multipliers even higher, see today's NBA parlay boosts. And if you have broader questions about how NBA parlay betting works day to day, the NBA parlay FAQ has you covered.