Parlay Calculator

Free parlay calculator for sports betting. Enter each leg's American odds — we'll calculate the combined odds, true win probability, and payout.

Leg 1
Leg 2
Leg 3
3/12 legs
Stake ($)
Combined odds
+811
Decimal
9.11
Win probability
10.98%
Payout
$91.12

Profit on a winning ticket: $81.12. Want to know if this parlay is +EV? Run it through the EV calculator or paste it into the Bet Analyzer.

How a parlay calculator works

A parlay combines multiple bets — every leg must win. To compute the combined odds, multiply each leg's decimal odds. For example, three −110 legs (decimal 1.91) → 1.91 × 1.91 × 1.91 ≈ 6.97, or about +597 American. The win probability is just 1 / combined_decimal.

Worked example — 3-leg NFL parlay

  1. 1
    Leg 1 — Bills −3.5 −110 (1.91 decimal)
  2. 2
    Leg 2 — Chiefs/Ravens Over 47.5 −110 (1.91 decimal)
  3. 3
    Leg 3 — Josh Allen Over 1.5 pass TDs +150 (2.50 decimal)
  4. 4
    Combined decimal: 1.91 × 1.91 × 2.50 = 9.12
  5. 5
    Combined American: ≈ +812
  6. 6
    Win probability: 1 / 9.12 = 10.96%
  7. 7
    $10 stake payout: $91.20
    Profit: $81.20
The combined fair price (devigging each leg first) would be around +880. So this parlay carries roughly 7% built-in hold — meaning you'd need a real edge somewhere to make it +EV. Drop it into the Bet Analyzer to see the breakdown.

Frequently asked questions

How do parlay odds work?+

Every leg must win. To compute combined odds, convert each leg to decimal odds and multiply them together. Three −110 legs (1.91 × 1.91 × 1.91) ≈ 6.97 decimal, or about +597 American.

Are parlays ever +EV?+

Yes, but rarely. Each leg compounds the book's vig, so a typical 3-leg parlay carries a 10–15% hold. To be +EV the combined fair price must beat the combined boosted price — which mostly happens during specific promos or correlated SGP markets that sportsbooks misprice.

What's the difference between a parlay and a same-game parlay (SGP)?+

A traditional parlay combines independent bets across different games. A same-game parlay combines correlated legs from one game. SGPs are priced under the assumption legs are independent, which often overprices them — but correlation in your favor can make them sharp.

How is parlay payout calculated?+

Payout = stake × combined decimal odds. Profit = payout − stake. A $10 bet at +597 returns $69.70 ($59.70 profit) if every leg hits.

Why do sportsbooks push parlays so hard?+

Margin. A single bet at −110 carries ~4.5% hold. A 5-leg parlay can carry 20%+ hold once each leg's vig compounds. Books promote parlays because they're the highest-margin product on the menu.