Free instant odds converter — switch between fractional, decimal and American (moneyline) formats and see the implied probability of any price.
Frequently asked questions
What is implied probability?
Implied probability is the bookmaker's stated chance of an outcome, calculated as 1 / decimal odds × 100. For example, decimal odds of 2.00 carry an implied probability of 50%. Use the converter to spot prices where your own estimated probability is higher — that is the definition of a value bet.
How do I convert fractional odds to decimal?
Divide the numerator by the denominator and add 1. For example, 5/2 becomes 2.50 + 1 = 3.50. The converter does this instantly for fractional, decimal and American formats.
Why do American odds use + and − signs?
Positive American odds (e.g. +200) show the profit on a 100-unit stake. Negative odds (e.g. −150) show the stake required to win 100 units. The converter normalises both into decimal so you can compare prices across markets quickly.