How to Calculate a Payoff for a Bet at the Kentucky Derby

Whether it’s the Kentucky Derby or green 2-year-old thoroughbreds battling out the first race of their careers, the rules for wagering and payoffs are the same for all American races. Horse racing is a pari-mutuel sport, which means that you place your wager into a pool with thousands of other bettors. If you win, you get a share of the pool.

Bets to Win

You might like Lucky Duck, and bet on him to win. If he goes off at 2-1 odds and does indeed win, multiply the first number -- 2 -- by the amount of your bet. If you bet $2, this comes out to $4. But you also get your wager back, so add this into the payoff as well. You’d come away with $6 on a $2 bet. If Lucky Duck went off at 20-1 odds, you’d win $42 on a $2 wager: two times $20 plus your $2 bet. With odds that don’t end in one, divide the first number by the second number, then multiply the result by the amount of your bet. Assuming you placed a $2 wager on a 7-5 horse, you’d win $4.80: 1.4 times two, plus your $2 bet.

Place and Show Wagers

If you bet Lucky Duck to place or come in second rather than win, your bet will still pay off if he comes in first. The horse you wager on must finish the same or better than the wager you placed on him for you to win money. So even if you bet on him to show or come in third, you'd collect money if he won -- he just did better than you anticipated. But the winning horse must share the place and show pools with the horses who actually come in second or third. The place pool is shared by the first and second place horses and the show pool is shared by the first, second and third place horses. Because all these horses usually go off at different odds, no easy calculation exists for figuring place and show payoffs.