Implied Probability Betting Calculator
True probability priced into one or more odds.
How to Use This Calculator
- Pick the odds format: Decimal, Fractional, or American
- Enter odds for a minimum of two outcomes (e.g. Team A and Team B)
- Append further outcomes where required (e.g. the draw in soccer)
- Read implied probability per outcome, the aggregate probability, and the bookmaker margin
An aggregate implied probability exceeding 100% reflects the bookmaker’s margin.
Formula
Implied Probability from Decimal Odds: Probability = (1 / Decimal Odds) x 100%
Bookmaker Margin: Margin = Total Implied Probability - 100%
No-Vig (Fair) Probability: Fair Probability = Implied Probability / Total Implied Probability
Frequently Asked Questions
Define implied probability.
Implied probability is the outcome likelihood signalled by the odds. It carries the bookmaker margin, so the aggregate always tops 100%.
Bookmaker margin — what is it?
The bookmaker margin (vig/juice) is the gap between aggregate implied probability and 100%. It is the bookmaker’s embedded profit.
How are value bets identified?
When your estimate of an outcome’s true probability exceeds the odds-implied probability, the bet carries positive expected value.