Data study · updated 2026-10-08
Parlay Reality Check
Every leg you add multiplies the payout — and the bookmaker’s margin. We calculated exactly how much, for 1 to 12 legs.
Key findingslegs priced at −110, both sides of each market at −110
- A single −110 bet carries a 4.55% bookmaker edge. A 10-leg parlay carries 37.20% — about 8.2× more.
- In the long run a 10-leg −110 parlay returns about $0.63 for every $1 staked; a single bet returns $0.95.
- A $100 five-leg parlay pays $2,535.91. With no margin it would pay $3,200.00.
- The true chance of hitting five fair coin-flip legs is 3.13% — about 1 in 32.
Bookmaker edge by number of legs
Spread/total at −110
Fair chance per leg 50.00% (bookmaker margin 4.76% removed proportionally). $100 stake.
| Legs | Odds | Pays | Fair pay | True chance | 1 in | House edge | $1 returns |
|---|---|---|---|---|---|---|---|
| Single | −110 | $190.91 | $200.00 | 50.00% | 2.0 | 4.55% | $0.95 |
| 2 | +264 | $364.46 | $400.00 | 25.00% | 4.0 | 8.88% | $0.91 |
| 3 | +596 | $695.79 | $800.00 | 12.50% | 8.0 | 13.03% | $0.87 |
| 4 | +1228 | $1,328.33 | $1,600.00 | 6.25% | 16.0 | 16.98% | $0.83 |
| 5 | +2436 | $2,535.91 | $3,200.00 | 3.13% | 32.0 | 20.75% | $0.79 |
| 6 | +4741 | $4,841.27 | $6,400.00 | 1.56% | 64.0 | 24.36% | $0.76 |
| 8 | +17545 | $17,644.64 | $25,600.00 | 0.39% | 256.0 | 31.08% | $0.69 |
| 10 | +64208 | $64,308.16 | $102,400.00 | 0.10% | 1,024.0 | 37.20% | $0.63 |
| 12 | +234279 | $234,379.33 | $409,600.00 | 0.02% | 4,096.0 | 42.78% | $0.57 |
Favorite at −200 (other side +170)
Fair chance per leg 64.29% (bookmaker margin 3.70% removed proportionally). $100 stake.
| Legs | Odds | Pays | Fair pay | True chance | 1 in | House edge | $1 returns |
|---|---|---|---|---|---|---|---|
| Single | −200 | $150.00 | $155.56 | 64.29% | 1.6 | 3.57% | $0.96 |
| 2 | +125 | $225.00 | $241.98 | 41.33% | 2.4 | 7.02% | $0.93 |
| 3 | +238 | $337.50 | $376.41 | 26.57% | 3.8 | 10.34% | $0.90 |
| 4 | +406 | $506.25 | $585.52 | 17.08% | 5.9 | 13.54% | $0.86 |
| 5 | +659 | $759.38 | $910.81 | 10.98% | 9.1 | 16.63% | $0.83 |
| 6 | +1039 | $1,139.06 | $1,416.82 | 7.06% | 14.2 | 19.60% | $0.80 |
| 8 | +2463 | $2,562.89 | $3,428.34 | 2.92% | 34.3 | 25.24% | $0.75 |
| 10 | +5667 | $5,766.50 | $8,295.74 | 1.21% | 83.0 | 30.49% | $0.70 |
| 12 | +12875 | $12,974.63 | $20,073.65 | 0.50% | 200.7 | 35.36% | $0.65 |
Underdog at +150 (other side −175)
Fair chance per leg 38.60% (bookmaker margin 3.64% removed proportionally). $100 stake.
| Legs | Odds | Pays | Fair pay | True chance | 1 in | House edge | $1 returns |
|---|---|---|---|---|---|---|---|
| Single | +150 | $250.00 | $259.09 | 38.60% | 2.6 | 3.51% | $0.96 |
| 2 | +525 | $625.00 | $671.28 | 14.90% | 6.7 | 6.89% | $0.93 |
| 3 | +1463 | $1,562.50 | $1,739.23 | 5.75% | 17.4 | 10.16% | $0.90 |
| 4 | +3806 | $3,906.25 | $4,506.18 | 2.22% | 45.1 | 13.31% | $0.87 |
| 5 | +9666 | $9,765.63 | $11,675.11 | 0.86% | 116.8 | 16.36% | $0.84 |
| 6 | +24314 | $24,414.06 | $30,249.14 | 0.33% | 302.5 | 19.29% | $0.81 |
| 8 | +152488 | $152,587.89 | $203,056.74 | 0.05% | 2,030.6 | 24.85% | $0.75 |
| 10 | +953574 | $953,674.32 | $1,363,081.26 | 0.01% | 13,630.8 | 30.04% | $0.70 |
| 12 | +5960364 | $5,960,464.48 | $9,150,105.43 | <0.01% | 91,501.1 | 34.86% | $0.65 |
Methodology
- Each leg is an independent two-way market. The “fair” chance removes the bookmaker margin proportionally (see our guide to the vig).
- Parlay odds are the product of the legs’ decimal odds — how standard (non same-game) parlays are settled.
- House edge = 1 − (payout × true chance) ÷ stake. All values are computed with exact fractions by the same tested engine behind our parlay calculator and rounded only for display (methodology).
- Not included: odds boosts, same-game parlay pricing (usually worse), and any edge a bettor may genuinely have.
- Real-world check: see our Illinois parlay data, built from state regulator reports, for how much bettors actually lose on parlays.
Use this data
Journalists and bloggers are welcome to quote or republish these figures with a link to this page. Questions or a custom cut of the data: [email protected].
By the slipmath Editorial Team. 18+/21+. Gambling can be addictive — get help.