Odds Formats Explained: Decimal, Fractional & American
The same betting price can be written three different ways. Here's what each one means and how to convert between them.
Decimal (e.g. 2.50)
The total return per $1 staked, including your stake back. A $10 bet at 2.50 returns $25 total ($15 profit). This is the format used on this site's own calculators.
Fractional (e.g. 3/2)
Profit relative to stake, written as a fraction. 3/2 means a $2 stake profits $3 (returns $5 total). Common in UK-style presentation.
American (e.g. +150 or -120)
Positive numbers show profit on a $100 stake (+150 = $150 profit on $100). Negative numbers show the stake needed to profit $100 (-120 = stake $120 to profit $100).
Converting between formats
- Fractional → Decimal: Decimal = (numerator ÷ denominator) + 1
- American (positive) → Decimal: Decimal = (American ÷ 100) + 1
- American (negative) → Decimal: Decimal = (100 ÷ |American|) + 1
Worked example
Decimal odds of 2.50 are the same price as fractional 3/2 and American +150. A $10 stake at any of these returns $25 total — a $15 profit.
Don't want to convert by hand? Use the Odds Converter tool — enter any format and see all three, plus the implied probability.