Combine 2 to 12 legs in American or decimal odds. Get the exact payout, profit, combined decimal odds, and combined implied probability, recomputed live as you type.
A parlay pays only if every leg wins, so the odds multiply. The math is exact, not an estimate. Here is the whole thing.
# 1. convert each leg to decimal odds American positive A -> decimal = A / 100 + 1 # +150 -> 2.50 American negative A -> decimal = 100 / |A| + 1 # -200 -> 1.50 Decimal odds -> used as entered # 1.91 -> 1.91 # 2. combine combined_decimal = product of all leg decimals payout = stake * combined_decimal profit = payout - stake implied_probability = 1 / combined_decimal
Building this into an app? You can pull the live odds that feed this calculation straight from ParlayAPI: the same market priced by 30+ sportsbooks in one response, so your parlay always uses the best available leg prices. Create a free API key or read the docs.
Convert every leg to decimal odds (positive American A becomes A/100 + 1, negative A becomes 100/|A| + 1), multiply the decimals together, then multiply by your stake. Profit is the payout minus the stake. The math is exact, not an approximation.
Each -110 leg is 1.9091 decimal, so three legs multiply to 6.9579 decimal, about +596 in American odds. A $100 stake returns $695.79 total ($595.79 profit). The combined implied probability is 14.37%.
Yes. Each leg has its own format selector. Every leg is converted to decimal odds internally before the legs are multiplied, so the formats can be mixed freely.
Because the legs multiply, the margin baked into each price multiplies too. If a -110 leg's true chance is 50%, its expected return is 0.50 x 1.9091 = 0.9545 of your stake, about a 4.5% edge against you. Three such legs compound to 0.95453 = 0.870, roughly a 13% expected loss. Comparing each leg to its no-vig fair price matters more with every leg you add.