Convert odds across major formats and understand the true probability behind each price.
Odds Conversion Calculator
Enter an odds value and select its format. The tool converts it to all other formats, shows implied probability, and optional profit if you add a stake.
Converted Odds & Implied Probability
Decimal Odds:
Fractional Odds:
American Odds:
Implied Probability:
Total Return:
Profit If Win:
Implied probability excludes margin; real market edges depend on true probability versus implied.
Converting odds clarifies the underlying probability, essential for detecting value and managing bankroll sensibly.
How Conversion Works
All formats map back to decimal odds, then probability is 1 / decimal. Fractional shows profit relative to stake; American shows profit units per 100 staked or stake needed to win 100.
Common Mistakes
Misreading negative American odds as positive.
Forgetting fractional odds exclude stake.
Using implied probability without adjusting for bookmaker margin.
Worked Examples
Decimal to Fractional and American
A European bookmaker offers odds of 2.50 on a tennis match. Enter 2.50 in decimal format and the calculator converts it to 3/2 fractional (common in the UK) and +150 American (common in the US). The implied probability is 40%. With a £10 stake, your potential return is £25 (£15 profit). This makes it easy to compare the same odds across different regional formats.
American to Decimal Conversion
A US sportsbook lists a favourite at -200. Enter -200 in American format and the calculator shows this equals 1.50 in decimal and 1/2 fractional. The implied probability is 66.7%. For a $100 stake, your potential return is $150 ($50 profit). Negative American odds always represent favourites — the number shows how much you must stake to win $100.
Comparing Odds Across Bookmakers
Bookmaker A offers 6/4 fractional on a football match, while Bookmaker B lists the same selection at +140 American. Convert both: 6/4 = 2.50 decimal (implied probability 40%), while +140 = 2.40 decimal (implied probability 41.7%). Bookmaker A offers better value — 2.50 vs 2.40 decimal gives you an extra 10 cents per euro staked. Always convert to the same format before comparing.
