Used widely in the USA, American odds are simply another way bookmakers present their chosen odds.
American odds use the plus and minus sign to convey the potential return for any bet. American odds always use a baseline value of $100. A negative number indicates how much you’ll have to bet to win $100, and a positive number indicates how much you’ll win if you bet $100. Therefore, a negative number indicates an ‘odds-on’ favourite.
Moneyline odds are the same as American odds. They are both a form of betting odds whereby prices are presented in multiples of 100 with plus and minus signs.
Using American odds, you may see bookmakers present odds in this format:
In this example, the Patriots are the favourite, because they have the negative odds. If you bet on the Patriots at -220, you must risk $220 to win $100 from the betting agency. If you bet on the Packers at +180 you risk only $100 but you win $180.
The easiest way to convert American odds is to use an odds converter calculator. But if you’d like the formula, here it is:
For positive American odds:
American odds ÷ 100 + 1
For negative American odds:
100 ÷ American odds + 1
So, using our example again:
+180 odds = 180 ÷ 100 + 1 = 2.8
-220 odds = 100 ÷ 220 + 1 = 1.45
Negative Moneyline odds will always convert into decimal odds with a price of less than $2.00.
Our odds converter is the easiest way to convert American odds to fractional odds. If you prefer the old-fashioned way, we provide the formula for you below:
For positive odds, divide American odds by 100 and reduce to the simplest form:
For negative odds, divide 100 by the American odds and reduce to the simplest form:
To reduce a fraction to its simplest form, determine the largest factor that is common between the two, and divide both the numerator and denominator by the greatest common factor. For example 9/27 is simply expressed as 1/3.