Parlay Calculator

How to use the parlay calculator

1. Pick the odds format your sportsbook shows: American (-110), decimal (1.91) or fractional (10/11).
2. Enter your stake in dollars, or switch to units if you size bets as a share of your bankroll.
3. Type the price of each leg. Add legs as you need them, up to 12.
4. If a leg pushed or was voided, press Push. It counts as 1.00, so the rest of the parlay pays at the reduced odds.
5. Read your parlay odds, profit, total payout and implied probability as you type.

Switching formats converts the prices you already entered instead of clearing them, so you can paste a line in one format and read it in another.

Parlay odds formula

A parlay multiplies the decimal odds of every leg:

parlay decimal = leg 1 × leg 2 × … × leg n
payout = stake × parlay decimal
profit = payout − stake

Worked example: three legs at -110. Each -110 leg is 1 + 100/110 = 1.9091 in decimal. Multiply them: 1.9091 × 1.9091 × 1.9091 = 6.958. Converting back, (6.958 − 1) × 100 gives +596: about +597, the figure you get by rounding each leg to 1.91 before multiplying (6.968). A $100 bet pays $695.79 in total.

Implied probability is 1 ÷ parlay decimal. For the three-leg ticket that is 1 ÷ 6.958 = 14.37%: the hit rate you need just to break even.

True parlay odds vs. what books pay

If every leg were a true coin flip, a fair parlay would double its payout with each leg. At the standard -110 price the book keeps a slice of every leg, and that slice compounds.

Same-game parlays

This calculator assumes every leg is independent. Legs in a same-game parlay are correlated — a quarterback’s passing yards and his receiver’s receiving yards tend to rise together — so sportsbooks don’t just multiply the prices. They apply their own correlation adjustment, usually paying less than the multiplied odds. Treat the result here as an upper bound for a same-game parlay, and trust the price your book quotes.