Probability Odds to Fractional Odds Converter

How to convert Probability odds to Fractional odds

Use this calculator to convert probability odds into fractional odds. Simply input a valid value and the calculator will automatically convert it into fractional odds.

Formula used for converting probability odds to fractional odds

Subtract 1 from the decimal odds and express the result as a fraction of two whole numbers.

For example, probability odds of 25% convert to fractional odds of 3/1.

Probability odds explained

Probability odds or implied probability is, as the name suggests, the underlying implied probability of the outcome occurring. It's not an odds format in the usual sense but implied probability is widely used by professional bettors in valuebetting and arbitrage betting. It can for example be used to compare the bookies priced odds to an estimated true probability derived from other data or a sharp bookie. Worth noting is that calculating the implied probability straight from the bookmaker odds doesn't take the bookmaker edge into account and requires all outcomes for an event to calculate the true underlying implied probability.

Fractional odds explained

Fractional odds are almost exclusively used in the UK and Ireland and is the traditional odds format there. Although most UK and Irish bettors are most used to the fractional odds, decimal odds have recently started to gain popularity. Fractional odds can be described as the ratio between the profit and the bet size. For example a fractional odds of 3/2 means for every $2 wagered the potential profit is $3.

Supported odds formats

This converter supports decimal odds, fractional odds, American odds, Hong Kong odds, Malay odds, Indonesian odds, and implied probability percentage.

Why use an odds converter?

Bookmakers and betting exchanges use different odds formats depending on region and market. An odds converter makes it easier to compare prices, understand implied probability, and analyze bets more accurately across different sportsbooks.

Popular Odds Conversions

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All Odds Conversions

Browse every supported betting odds conversion by starting format.