Sports Betting Parlay Builder

Build a parlay from your own inputs

Add up to four selections by entering each leg’s American odds and your estimated win probability. The builder multiplies the prices and, under an independence assumption, multiplies the probabilities. It reports combined odds, potential return, break-even probability, and estimated expected value.

This is a manual planning tool. It does not search sportsbook markets, create a sportsbook ticket, or validate the probability estimates.

Compare the parlay price with your estimate

A positive expected value result means the combined payout exceeds the calculated break-even price under the probabilities entered. If selections are correlated, use a joint probability rather than multiplying each leg separately. Same-game parlay prices commonly account for correlation.

For example, two independent legs each estimated at 55% have a combined probability of 30.25%. Correlated game outcomes can make the true joint chance higher or lower.

Keep parlay risk visible

Parlays concentrate risk because one losing leg can defeat the full wager. The payout grows with added legs, but the chance of every leg winning generally falls. Compare the offer with a realistic joint model and read the sportsbook’s void-leg rules.