Free tool
Parlay Calculator
Add your legs and see the true combined odds, payout, and implied probability. Parlays multiply the house edge with every leg — this tool helps you see what you're actually getting.
Legs (3)
1
2
3
$
Payout if all legs hit
$200.45
+$175.45 profit
Combined odds
American+702
Decimal8.018
Implied win %12.47%
Legs3
The math — and the catch
Parlays multiply decimal odds: a 3-leg parlay at -110 each multiplies to ~6.88 decimal (+588). Big payout, but all three have to hit.
Why books love parlays: the vig compounds. A 3-leg parlay at -110 per leg has an implied probability of ~17.4% for the book — but the true probability (at fair -105 lines) would be closer to ~19.3%. That ~2% difference is the book's hold, multiplied across every leg.
Parlays are a fine tool for small, entertaining bets. For serious ROI, stick to single-leg +EV plays.