Odds Converter

Understanding Odds Formats

Decimal: Most common in Europe and Australia. Shows total return including stake (e.g., 2.50 means $2.50 return for every $1 bet)

American: Used in the US. Positive (+150) shows profit on $100 bet, negative (-110) shows amount to bet for $100 profit

Fractional: Traditional UK format. Shows profit relative to stake (e.g., 3/1 means $3 profit for every $1 bet)

Implied Probability: The likelihood of an outcome based on the odds

Conversion Results

Decimal: -

American: -

Fractional: -

Implied Probability: -

Worked example

Enter decimal odds of 2.50:

All three describe the identical bet — a $1 stake at 2.50 decimal odds returns $2.50 total (your $1 back plus $1.50 profit), which is exactly what +150 American odds and 3/2 fractional odds also pay out.

Why the American odds formula splits at 2.00

American odds use different arithmetic for favorites versus underdogs. Decimal odds ≥ 2.00 (underdogs, more than even money) convert as (decimal − 1) × 100, giving a positive number. Decimal odds below 2.00 (favorites) convert as −100 / (decimal − 1), giving a negative number — for example, decimal 1.50 becomes −100/0.50 = −200, meaning you'd need to stake $200 to profit $100.

A note on implied probability

The percentage shown is the break-even probability implied by the odds, not the bookmaker's true assessment of the outcome's likelihood — bookmakers build in a margin (the "vig"), so the implied probabilities across all outcomes in a market typically sum to more than 100%.