Implied Probability Betting Tool
Reveal the true probability implied by bookmaker odds across one or more outcomes.
How to Use This Calculator
- Choose the odds format you intend to use (Decimal, Fractional, or American)
- Enter the odds for a minimum of two outcomes (for example, Team A and Team B)
- Include further outcomes where appropriate (such as the draw in soccer)
- Review the implied probability of each outcome, the combined total, and the bookmaker margin
Whenever the total implied probability climbs above 100%, that surplus 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
What exactly is implied probability?
Implied probability is the chance of an outcome as expressed by the odds. Because it carries the bookmaker’s margin within it, the combined total across all outcomes always comes to more than 100%.
How is the bookmaker margin defined?
The bookmaker margin, also known as the vig or juice, is the gap between the summed implied probabilities and 100%. That gap is the profit the bookmaker has built into the market.
How can I identify value bets?
When your own estimate of an outcome’s true probability exceeds the implied probability drawn from the odds, the wager carries positive expected value.