De-vigging converts sportsbook odds into no-vig fair probabilities by removing the market overround. The method choice controls how that overround is allocated across outcomes, which matters most in asymmetric markets and 3-way markets.
Calculator · Free
De-vig the market, then compare price.
Enter two to four outcome prices and remove the book margin. The calculator returns fair probability, fair decimal odds, fair American odds, and market vig.
Market inputs
Outcome 1
Outcome 2
Power fits an exponent that can move probability toward or away from favorites. Additive subtracts an equal share of the vig from each implied probability. Multiplicative, also called proportional, scales each implied probability down by the market total.
Market vig
4.762%
Power no-vig prices
| Outcome | Fair probability | Fair decimal | Fair American |
|---|---|---|---|
| Outcome 1 | 50.00% | 2.0000 | -100 |
| Outcome 2 | 50.00% | 2.0000 | -100 |
Show your work
Step 1 - convert odds to implied probabilities
Outcome 1: 1 / 1.9091 = 52.381%
Outcome 2: 1 / 1.9091 = 52.381%
Step 2 - market overround
sum implied = 104.762%
vig = 104.762% - 100% = 4.762%
Step 3 - Power no-vig allocation
Outcome 1: fair 50.00%, decimal 2.0000, American -100
Outcome 2: fair 50.00%, decimal 2.0000, American -100De-Vig FAQ
What does de-vig mean?
De-vig means removing the sportsbook margin from the listed odds so the outcome probabilities sum to 100%. The result is a fair no-vig price for each outcome.
Which de-vig method should I use?
Multiplicative is the standard baseline for balanced markets. Power is useful when favorite and longshot treatment matters. Additive is a transparent constant-vig adjustment, but it can fall back on extreme markets.
Why do fair probabilities not sum to the book's implied probabilities?
Book implied probabilities include margin, so their sum is often above 100%. Fair probabilities remove that margin and normalize the market back to 100%.
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