Boneyard Tools

Betting Odds Converter

Enter odds in decimal, fractional or American (moneyline) format and instantly see the other two formats plus the implied win probability. Useful for comparing prices across sportsbooks.

How to convert betting odds

  1. Pick the format you have: decimal, fractional or American.
  2. Type the odds, for example 6.0, 5/1 or +500.
  3. Read the other formats and the implied probability instantly.

Examples

Decimal to everything

Decimal 6.0
Fractional 5/1, American +500, implied 16.67%

Frequently asked questions

How do decimal odds become a probability?

Implied probability equals 100 divided by the decimal odds. So decimal 4.0 implies a 25 percent chance.

What do positive and negative American odds mean?

Positive odds show profit on a 100 stake, like +500 wins 500. Negative odds show the stake needed to win 100, like -150 risks 150.

How are fractional odds related to decimal?

Fractional odds show profit over stake. Add 1 to the fraction to get decimal, so 5/1 equals 6.0 and 1/2 equals 1.5.

Why is the fractional value an approximation?

Fractional odds use whole numbers, so some decimal prices map to the nearest simple fraction rather than an exact match.

Does the implied probability include the bookmaker margin?

Yes. The implied probability comes straight from the offered odds, which include the bookmaker's built-in margin or vig.

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