Skip to content
SportsBookISH
Start free
← Tools
Parlay calculator

Parlay calculator

Enter 2-12 legs of American odds + your stake. We'll compute the actual parlay payout, the fair (no-vig) payout for comparison, and exactly how much you're paying away in compounded vig.

Legs (American odds)
Leg 1
Leg 2
Leg 3
3-leg parlay: +811 (decimal 9.11)
Implied prob: 10.98%
Book payout
$91.12
Profit: $81.12
Fair-value payout (no-vig)
$104.61
If books charged zero vig
Vig cost: 12.9%of the fair payout, eaten by compounded vig across 3 legs.

Reminder: parlay vig compounds. A 4-leg parlay of -110 bets has roughly 16-20% total vig vs ~4% on a single bet. Most parlays are -EV unless legs are positively correlated AND the book doesn't price the correlation.

The math

For each leg, convert American odds to decimal and to implied probability. Then:

Parlay decimal odds = leg1_decimal × leg2_decimal × ... × legN_decimal
Parlay profit = stake × (parlay_decimal − 1)
Implied prob (raw) = 1 / parlay_decimal

For "fair" comparison:
  no_vig_per_leg = leg_implied / (leg_implied + opposite_side_implied)
  ... but we only have one side. Simpler: assume each -110 leg de-vigs
  to ~50% (the book median for game lines), and apply that to each leg.

The fair-value payout shows what the parlay wouldpay if the book charged zero vig. The difference between the book's payout and the fair payout is the parlay's effective cost to you, expressed as a percentage of stake.

See parlay glossary entry for more on when (rarely) parlays are +EV.

Parlay calculator — FAQ

What is a parlay?
A parlay combines two or more individual bets into a single wager. All selections (legs) must win for the parlay to pay out. If even one leg loses, the entire parlay loses.
How is a parlay payout calculated?
Multiply the decimal odds of each leg, then multiply that product by your stake to get the total return (including stake). Example: three legs at decimal 1.91 each → 1.91^3 = 6.97. A $10 parlay pays $69.70 ($59.70 profit).
Are parlays +EV?
Almost never. Each leg has its own vig built in (typically 4-5% for game lines, 8-12% for props). The parlay compounds those vigs, so a 4-leg parlay of -110 bets has approximately 16-20% total vig vs ~4% on a single bet. Books love parlays because the math overwhelmingly favors them.
When can a parlay be +EV?
Correlated parlays where the legs are positively correlated AND the book doesn't price the correlation correctly. Same-game parlays of 'Team X wins big' + 'Total over' can be value plays when offensive shootouts are likely. Sharp books now price most correlations explicitly, so this edge is mostly gone in 2026.
What's the difference between parlay and same-game parlay?
A traditional parlay combines independent events from different games. A same-game parlay combines outcomes from one game (Patrick Mahomes over 275 yards + Chiefs to win + Total over). Books price same-game parlays with correlation adjustments, usually making them slightly worse value than uncorrelated parlays.