One price, three formats
Decimal 2.50 = fractional 3/2 = American +150. A winning stake of 10 returns 25 including the stake.
Decimal = 1 + fractional numerator ÷ denominator. Positive American odds convert as 1 + odds ÷ 100; negative odds as 1 + 100 ÷ absolute odds.
Converted fractions and American odds may be rounded.
Illustrative calculations only. No calculation establishes the true chance of winning.