How to read betting odds
A plain-English primer on Decimal, Fractional, and American odds — with conversion examples and a quick way to spot value.
Odds tell you two things at once: how much you stand to win, and how likely the bookmaker thinks an outcome is. The number is the same — only the format changes.
The three formats
Decimal (European)
Multiply your stake by the decimal price to see your total payout, including the stake. £10 at 2.50 returns £25 (£15 profit).
Fractional (UK)
The numerator is the profit per the denominator staked. 5/2 means £5 profit for every £2 staked. To convert to decimal: (numerator / denominator) + 1. So 5/2 = 3.50.
American
Positive numbers (e.g. +150) show the profit on a £100 stake. Negative numbers (e.g. −200) show the stake required to win £100. +150 = 2.50 decimal; −200 = 1.50 decimal.
Implied probability
Divide 1 by the decimal odds and multiply by 100. A price of 2.50 implies a 40% chance. If you reckon the true chance is higher than that, you have a value bet.