Implied Probability Calculator
Enter any betting odds and instantly see the implied probability. Add multiple outcomes to compute the bookmaker overround (vig) and the no-vig fair probability.
| Outcome | Implied % | No-vig % |
|---|---|---|
| Home win | 47.62% | 46.08% |
| Draw | 29.41% | 28.46% |
| Away win | 26.32% | 25.46% |
Overround = total implied − 100%. Margin = overround / total implied. No-vig (fair) prob = each outcome's implied divided by total implied.
What is the Implied Probability?
The implied probability calculator converts decimal odds to implied probability and shows the bookmaker's margin (vig / overround). Add multiple outcomes to remove the vig and see the no-vig fair probability for each outcome.
How to use the Implied Probability
- Enter at least 2 outcomes - for example "Home", "Draw", "Away" for a football match.
- Enter the decimal odds for each outcome.
- The implied probability per outcome appears in the right table.
- The total implied probability minus 100% is the bookmaker overround (margin).
- The no-vig column shows what each outcome's true probability would be if the bookmaker took zero margin.
The formula
Implied Probability = 1 / Decimal Odds
Total Implied = sum of all outcomes' implied probabilities
Overround = Total Implied − 1
Bookmaker Margin = Overround / Total Implied
No-vig Fair Probability = Outcome's Implied / Total ImpliedWorked example
A typical World Cup 2026 match might be priced at:
- Home win: 2.10 → 47.62% implied
- Draw: 3.40 → 29.41% implied
- Away win: 3.80 → 26.32% implied
Total implied = 103.35%. Overround = 3.35%. Bookmaker margin = 3.24%.
No-vig fair probabilities: Home 46.08%, Draw 28.46%, Away 25.46%. These are what the prices would be without the bookmaker margin - useful for comparing to your own model.
Get no-vig odds from Pinnacle and Betfair Exchange via API
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Frequently Asked Questions
What is implied probability?
The probability of an outcome implied by the odds. For decimal odds of 2.00, the implied probability is 50% (1 / 2.00). Bookmakers price odds so that the total implied probability across all outcomes is over 100% - the difference is their margin.
What is the bookmaker overround?
The amount by which a bookmaker's implied probabilities exceed 100%. A typical pre-match football overround is 2-7%; Pinnacle is usually 2-3%; recreational books can be 7-10%+.
What is no-vig (fair) probability?
The estimated true probability of each outcome with the bookmaker margin removed. Calculated by dividing each outcome's implied probability by the total implied across all outcomes.
How do I use no-vig odds?
Compare them to your own model. If your model says Mexico should win 50% of the time but the no-vig fair price is 46%, you have a 4% edge. Pinnacle's closing line (the no-vig version) is the standard benchmark for model validation.
Why do bookmakers add a margin?
It's how they make money. The margin guarantees a positive expected return per matched market over the long run, regardless of which outcome happens.
Which bookmaker has the lowest margin?
Pinnacle is widely considered the sharpest book with the lowest margins (often 1-2.5% on football match-result markets). Betfair Exchange is even lower (effectively the commission rate, ~2-5%) because it's peer-to-peer.