Enter market odds to remove the bookmaker margin and estimate no-vig fair probabilities.
Method
The calculator converts every outcome price into implied probability, adds those probabilities to measure overround, and then divides each probability by the total. The normalized values sum to 100% and provide a simple market-based fair probability estimate.
Educational example
If both sides are priced at 1.91, each raw implied probability is about 52.36% and the total is about 104.71%.
Normalizing both sides gives a simple no-vig estimate of 50% each. This is a proportional method, not a complete market model.
Turn a quoted market into a 100% probability distribution.
Compare overround across books or market types.
Use the no-vig estimate as one reference rather than treating it as ground truth.
Proportional normalization assumes margin is distributed evenly relative to implied probability. Favorite-longshot bias, exchange fees, stale lines, and asymmetric pricing can require more advanced methods.
Vig is the bookmaker margin embedded in the combined market prices.
They estimate a market consensus after one margin adjustment; they do not guarantee accuracy.
Yes. Normalization is meaningful only when the entered outcomes cover the complete mutually exclusive market.