Gambling odds are presented in one of three methods: Fractional, American and Decimal. Sports bettors need to become very familiar with the calculations and often the conversion of these odds (as you can do using the quick odds calculator on the right).
To convert odds from Fractional Odds to Decimal Odds, simply divide the numerator by the denominator and then add 1.
To convert decimal odds to fractional odds, simply subtract 1 from the decimal, and then convert the remaining decimal number into a fraction.
To convert American odds (positive) to a decimal, divide the odds by 100 and add 1. For example: (+300/100) + 1 = 4.00
To convert negative American odds into decimal odds, divide 100 by the odds number, (known as the “moneyline”), and add 1. For example: (100/300) + 1 = 1.33
To converting American odds into fractional odds, simply divide the odds by 100, and then simplify the equation. So 300/1 can be represented as 3/1.
And finally, for fractional odds, we divide 100 by the money line odds, and then simplify it. For example: 100/300 is the same as 1/3.