Multi-leg parlay payout calculator

How it works

A parlay multiplies the decimal odds of every leg together. Two legs at +100 (decimal 2.00) combine to 2.00 × 2.00 = 4.00× your stake — +300 in American odds. American lines convert to decimal first:

• Positive lines (e.g. +150): decimal = (line ÷ 100) + 1 → 2.50
• Negative lines (e.g. −110): decimal = (100 ÷ |line|) + 1 → 1.91

Payout = wager × the combined decimal; profit = payout − wager. The implied probability is the inverse of the multiplier: implied % = 100 ÷ parlay decimal.

Implied probability vs. true odds

A 5-leg parlay of all −110 legs multiplies to about 25.4× — an implied win probability around 3.9%, but the book pays it like it happens more often than it does. Every leg carries its own vig, and a parlay compounds the vig with each leg you add. To break even long-term, your real win rate on each leg has to be materially better than the line suggests, since every leg has to hit independently.

What this doesn't handle

Round-robins, same-game-parlay correlation discounts, and pushed legs are not modeled. Treat the multiplier as the unadjusted product of the legs you enter.

Related betting tools

• Odds converter — American, decimal, fractional, and implied probability, plus a no-vig two-sided mode.
• Hedge bet calculator — one leg left on a live ticket? Lock in equal profit either way.
• Implied team total calculator — turns a spread and over/under into each team's expected points, the fastest start/sit read the betting market offers.