The formula to convert fractional odds to decimal is as follows: (numerator/denominator) + 1 = decimal odds. How do you convert fractional odds to American? For fractions greater than 1, the formula is as follows: (fractional value) * 100 = American odds.

For conversion of fractional odds to decimal take the first figure and divide it by the second figure then add 1.00. So 1/2 becomes 1 2 + 1.00 = 1.50. Or 2/1 becomes 2 1 + 1.00 = 3.00.