Implied Probability Calc
The true chance baked into the odds, for one outcome or many.
How to Use This Calculator
- Pick your odds format (Decimal, Fractional, or American)
- Drop in odds for at least two outcomes (say, Team A and Team B)
- Tack on extra outcomes when you need them (for a soccer draw, for instance)
- Read off the implied probability per outcome, the total probability, and the bookmaker margin
When the total implied probability tips over 100%, that surplus 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 exactly is implied probability?
Implied probability is the chance of an outcome as the odds suggest it. The bookmaker’s margin is baked in, which is why the total always lands above 100%.
What's the bookmaker margin?
The bookmaker margin — also called the vig or juice — is the gap between the combined implied probabilities and 100%. That gap is the bookmaker’s guaranteed cut.
How do I spot value bets?
When you reckon the true probability of an outcome beats the implied probability baked into the odds, that wager carries positive expected value.