Decimal odds to fractional odds
You get the fraction that matches the decimal exactly, and the simplest fraction that rounds to it, since 1.33 is usually written 1/3, not 33/100.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter decimal odds.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Fractional = decimal − 1 written as a simplified fraction. The simplest fraction is the one with the smallest denominator that rounds to the same decimal at the same number of places.
Example
Inputs: Decimal odds = 1.33. Result: Exact fractional odds: 33/100; Implied probability: 75.188%.
Limits and caveats
- The simplest fraction depends on how many decimal places you typed: 1.3 gives a different fraction from 1.33. Beyond 4 places it equals the exact fraction.
- Implied probability includes the margin of whoever set the price and is not the true chance.
Questions about this tool
How do I convert 2.50 to a fraction?
Subtract 1 to get 1.5, which is 3/2.
Why are there two fractions in the result?
The first matches the decimal exactly; the second is the simplest fraction that rounds to the same decimal, such as 10/11 for 1.91.
What does a minus sign mean in American odds?
It is the stake needed to win 100: −200 means staking 200 to win 100, which is 1.50 in decimal.