How to Bet On Sports  Betting Odds Formats Guide
BETTING ODDS EXPLAINED
So you’ve opened a betting account and you’ve logged in. While the teams and names might look familiar to you, all those weird numbers around them are confusing. Those are simply odds that are posted on the board.
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BETTING ODDS
There are three main ways they are presented: American, fractional and decimal. Each style is a little bit different, so let’s delve into them to get a better understanding.

American Odds
When you’re looking at American odds, the first thing you’re going to want to notice is the sign in front of the odds as that denotes two very different things. If there is a minus sign in front of the odds – or a negative number – then that indicates the amount of money you’d have to bet to win $100. If there is a plus sign, that indicates how much money you’d win if you bet $100. For example:
• New York Yankees 140
• Boston Red Sox +120In this case scenario, a $140 on the Yankees would pay you $100 if it won. As for the Red Sox, a $100 bet would net you $120 if it won. Of course, you don’t have to bet in exactly $100 increments as the examples above show. Once you understand the ratios, you can plug in whatever numbers you would like.
When you’re looking at you’re matchup, the option with the smallest negative number is the favorite for the event. The option that has the larger number is the underdog. 
Fractional Odds
Fractional odds appear as – you guessed it – fractions. That can mean numbers like 10/1 or 9/2 or 15/1. To calculate your payout with these odds, it’s quite simple: your stake is the denominator and the payout is the numerator. So if you want to bet $50 on a bet where the payout is 15/1, you would plug in 50 on the bottom. Then you would multiple the top part by 50 as well to get your potential payout, which in this case is $750. Fractional odds are often associated with futures, such as the odds to win the Super Bowl, horse racing, golf and racing events.

Decimal Odds
The third option that is commonly used to display the odds is decimal form. In this case, we’re essentially changing the fractions to decimals. If you remember your Grade 6 math, then it shouldn’t be a problem for you. With decimals, calculating your payout is quite simple: just multiple your stake by the decimal odds to get your total payout. It’s the easiest form of odds to calculate.
With decimal odds, the team or option with the smallest decimal number is the favorite whereas the choice with the biggest number is the underdog. As the numbers grow larger, those selections are greater and greater underdogs
If you’re interested in converting American odds to decimal, you can use this equation when you’re dealing with a negative number. If a team is 110, what you would do is take 100, and divide it by 110 (the odds). Then you add one to that number to get the decimal. In this case, you would get 0.909090 and then it would be 1.909090 after adding one.
Decimal odds are more popular in nonAmerican markets. A lot of the sportsbooks in the United Kingdom use decimals odds as do the Asian markets. In North America, the American style of odds is the standard.