Calculating horse racing odds involves figuring out the betting odds or payout for your money and the chance you have of winning. It requires knowing, and correctly using, the information presented on the toteboard. You also need to know the "take" at your track. The rest is simple mathematics.
Read the toteboardFirst, you will need to obtain a couple of figures from the toteboard. Look for the total win pool. This is the total amount of money bet on all horses in the race. You also need the total amount bet on the horse you are calculating odds for.
Find out the take at your trackThe take is how much the track takes out of the total win pool as a profit. It varies from state to state, but is usually 14 to 20 percent.
Calculate the betting oddsSubtract the take from the total pool; for example, $910 - 15 percent = $773.50. From that number, subtract the total amount bet on your horse ($773.50 - $70 = $703.50). The resulting number is the actual amount to be paid out ($703.50). Finally, divide the amount to be paid out by the amount bet on your horse to get the exact odds for you bet on ($703.50/$70 = $10.05). Odds are usually rounded down to the nearest dime in this case $10.00. This means that for every $1 you bet on your horse, you will get a $10 return if he wins (10:1 odds).
Calculate odds of winningFrom the betting odds, you can easily calculate the chance you have of winning. Divide the right number by the sum of the two numbers. In the previous example (10:1), divide 1 by 11 to get 0.09 or a 9 percent chance of winning.