How to Calculate Parlay Odds

A parlay in boxing (or any sport) is when you combine multiple picks into one bet for a bigger payout. The catch: you need *all* legs of the parlay to win, or the whole bet loses. Calculating parlay odds is straightforward if you break it down: convert each leg’s odds to decimal, multiply them together, then convert back to your desired format or just multiply by your stake to see the payout. Each leg’s odds compound the others.

Step-by-step: Suppose you want to parlay three fighters:

* Fighter A at -110, Fighter B at -200, and Fighter C at +150. First, convert to decimal odds: -110 = 1.91 (since -110 means you get \$1.91 for each \$1 wagered, including stake), -200 = 1.50, +150 = 2.50. Next, multiply the decimals: 1.91 × 1.50 × 2.50 = 7.1625. This 7.1625 is the combined decimal odds for the parlay. If you bet \$100 on this parlay, your total payout would be 7.1625 × \$100 = \$716.25. That includes your stake, so the profit is \$716.25 - \$100 = \$616.25. In American odds terms, that’s roughly +616 odds (about 6.16-to-1).

You can check the math by breaking it down: If all three fighters win, \$100 would turn into \$191 with A, then roll that \$191 onto B would make \$286.50, then onto C would make \$716.25. Same result. The formula works for any number of legs – just keep multiplying the decimals.

Most of us don’t want to do manual calculations every time – and you don’t have to, since online books or calculators do it. But it’s good to know the math so you understand what kind of payout you’re getting and how each leg affects it. Key insight: parlays exponentially increase risk *and* reward. Adding more fights will boost the payout a lot, but the chance of winning drops. For example, a two-leg parlay of two -110 picks pays about +264 (2.64-to-1); a three-leg of -110s pays roughly +596 (almost 6-1). Notice it roughly doubled the payout adding that third leg. Each additional leg multiplies your odds, but also multiplies the things that can go wrong.

Correlated outcomes caution: In boxing, parlays are usually straightforward since fights are independent. But avoid parlays of outcomes from the same fight if the book even allows it (most don’t, unless it’s a special same-game parlay offer). For instance, “Fighter wins and over 8.5 rounds” are correlated – they’re not independent events – so the math isn’t just multiplying odds (and books adjust for that). Generally, stick to parlaying different fights, or a fight outcome with another sport’s bet, etc.

When to parlay: Many bettors parlay heavy favorites to get a better payout. E.g., parlaying two big favorites like -500 and -400 might give around -200 combined odds (depending on exact lines). This can be a way to bet two expected winners for a bit more value. Just remember if even one slips on a banana peel, your parlay busts. Some also parlay an underdog with a favorite to pump the payout – that’s fine, but consider if you’d be better off betting them straight. A general rule: don’t parlay just for the sake of a lottery ticket; have a reason you like each leg. Sportsbooks love to advertise big parlay wins, but they usually make good money off parlays because of the difficulty.

In summary, calculating a parlay is multiplying probabilities. The math is easy: multiply the odds (or implied probabilities) of each leg. The result shows why parlays pay so much – you’re asking for multiple outcomes to all occur. Understand that and you’ll use parlays more wisely. They’re fun and can juice up your payout, just be aware of the trade-off: higher reward, much lower probability to hit. Small parlays (2-3 legs) can be a reasonable tactic if you find it hard to lay big money on single huge favorites – but don’t get too carried away with 6- or 10-leg parlays chasing monster payouts. The math says those are long shots for a reason.

Sources: Investopedia