American Odds to Fractional Odds Converter
How to convert American odds to Fractional odds
Use this calculator to convert American odds into fractional odds. Enter a valid value and the converter will instantly return the equivalent fractional odds value.
How American odds are converted to fractional odds
The simplest method is to convert American odds into decimal odds first, then convert the decimal odds into fractional odds. This reduces sign errors and keeps the calculation consistent across different betting formats.
For example, American odds of +150 convert to fractional odds of 3/2.
Worked example
Convert American odds of +100 to fractional odds
Since +100 is positive, divide by 100 to get the profit-per-unit figure.
100 / 100 = 1.00.
Convert 1.00 into a simplified fraction.
The fractional odds are 1/1.
Important note for this conversion
This conversion is useful when one bookmaker lists a market in American odds and another shows the same market in fractional odds.
Common conversion mistake
A common mistake with American odds is forgetting that positive and negative values use different formulas. Always check the sign before converting.
American odds explained
American odds are built around a 100-unit reference point. If the number is positive, it represents profit from a 100 stake. If it is negative, it represents the stake needed to win 100. This format is especially common in betting on US sports such as the NFL, NBA, MLB, and NHL.
Fractional odds explained
Fractional odds express the relationship between profit and stake as a ratio. For example, 5/1 means 5 units of profit for every 1 unit bet, while 1/2 means 1 unit of profit for every 2 units staked. This format is still common in horse racing and UK-facing sportsbooks.
Supported odds formats
In addition to converting American odds into fractional odds, the underlying calculator supports the main odds formats used worldwide. This includes decimal, fractional, American, Hong Kong, Malaysian, Indonesian, and probability-based pricing.
Why use an odds converter?
A American odds to fractional odds conversion is useful when researching bets across multiple regions or bookmakers. Instead of mentally translating between formats, you can compare the same price in a form that is easier for you to understand.
Frequently asked questions
What is the easiest way to convert American odds to fractional odds?
In most cases, the easiest method is to convert American odds into decimal odds first and then convert the decimal odds into fractional odds.
Why do bettors convert American odds into fractional odds?
Bettors often convert American odds into fractional odds to compare bookmaker prices more easily, understand implied probability, and read markets in the format they are most comfortable with.
Can I compare bookmakers more easily after converting American odds to fractional odds?
Yes. Once both prices are in the same format, it becomes much easier to spot value differences, compare payout levels, and evaluate whether one bookmaker is offering a better line than another.
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