Odds Converter Calculator

Decimal odds represent the total return per £1 staked, including your stake. Odds of 2.50 mean a £10 bet returns £25 (£15 profit + £10 stake). They are the most common format in Europe, Australia, and Canada, and are the easiest to compare across markets.

Fractional odds show your profit relative to your stake. Odds of 3/2 mean you win £3 for every £2 staked. They are the traditional UK and Irish format, still commonly displayed on horse racing markets. Fractional odds do not include your stake in the return figure.

American odds use a +/- system centred on £100. Positive odds (e.g. +150) show profit on a £100 stake. Negative odds (e.g. -110) show how much you must stake to win £100 profit. This format is standard in US sportsbooks and is increasingly used globally.

Decimal odds are generally the easiest for value betting because converting to implied probability is a single division: 1/decimal. Fractional and American formats require extra steps. Most professional bettors work in decimal odds even when comparing against UK bookmakers who display fractions.

Fractional odds are traditionally shown as simple round fractions (e.g. 5/4, 11/8). This calculator converts precisely from decimal, which can produce less conventional fractions like 127/100. Bookmakers round to nearest traditional fractions, so small differences are normal.