No-vig fair odds calculator
Enter both sides of a line, like an Over and its Under, to strip out the book's margin and see the fair price for each.
How it works
Each price implies a probability: 1 divided by its decimal odds. On a -130 / +110 line that's 56.5% and 47.6%, which add to 104.1%. The extra 4.1% is the book's margin. Dividing each side by the 104.1% total gives the fair probabilities, 54.3% and 45.7%, and turning those back into odds gives the no-vig prices.
Questions
What are no-vig odds?
The price a line would have if the sportsbook took no margin. Remove the vig from both sides and what's left is the market's honest estimate of each side's chance.
Why would I want fair odds?
To know whether a price is good. If the fair price on an Over is +105 and another book offers +120, that book is paying more than the bet is worth. That gap is your edge.
Which book should I de-vig?
The sharpest one you can find, usually a high-limit book or an exchange, because their prices move fastest when new information arrives. De-vigging a soft book just gives you that book's opinion.
Is this the multiplicative method?
Yes. Each side's implied probability is divided by the total, which is the standard method. Other methods (additive, power, Shin) shift a little more of the margin onto longshots, but on a close two-way line they agree within a point or two.
Find prices that beat the fair line
Betravon compares every book on every player prop and flags the ones priced out of line with the rest of the market.
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