Implied Probability Helper
Find the real chance hidden in bookmaker odds for one or more outcomes.
How to Use This Calculator
- Choose the odds format you’re using (Decimal, Fractional, or American)
- Type in the odds for at least two outcomes (for instance, Team A and Team B)
- Add extra outcomes whenever you need them (such as a draw in soccer)
- Check the implied probability for each outcome, the total probability, and the bookmaker’s margin
Whenever the total implied probability comes out above 100%, that extra slice is 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
What is implied probability?
Implied probability is how likely an outcome is according to the odds. Because it folds in the bookmaker’s margin, all the outcomes added together always come to more than 100%.
What does the bookmaker margin refer to?
The bookmaker margin (also called the vig or juice) is the gap between the total implied probabilities and 100%. That gap is the bookmaker’s built-in profit.
How can I spot value bets?
If you reckon the real chance of an outcome is greater than the implied probability shown by the odds, then that bet carries positive expected value.