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No-vig fair odds calculator

Remove the vig from any market, two-way or up to six outcomes, with multiplicative, additive, power, Shin and probit side by side, the solved constant for each, and the worst case for the side you bet.

FreeNo account neededSame math as our tools

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Run this math on every line, automatically

Our tools devig every book this way and blend them by your preset and weights into one fair price per line.

See fair lines on the Odds ScreenLearn how it works

How it works

A book's prices imply probabilities that add to more than 100%; the excess is its margin (the hold). Removing it ("devigging") gives fair probabilities that add to exactly 100%. The methods differ in where they take the margin from:

Multiplicative: pi = qi ÷ Σq (proportional to price)

Additive: pi = qi − (Σq − 1)/n (equal share from each side)

Power: pi = qik, k solving Σ qik = 1 (more from longshots)

Shin: models a share z of insider money; equals additive on two-way markets

Probit: pi = Φ(Φ−1(qi) − c), one shift c on the normal scale

On near-even markets (−110/−110) every method agrees. They differ on lopsided markets and on three-way markets with a longshot, which is where the choice matters. Probit is our default because published comparisons find it among the best calibrated, and it is what our tools use unless you change it.

Worked example

A soccer 1X2 market: home +150, draw +240, away +190. Booksum 103.89%, so the hold is 3.89%. The five methods remove it differently:

OutcomeImpliedMult.AdditivePowerShinProbit
Home +15040.00%38.50%38.70%38.69%38.65%38.63%
Draw +24029.41%28.31%28.11%28.13%28.16%28.19%
Away +19034.48%33.19%33.18%33.18%33.19%33.18%

On this fairly balanced market the methods stay within a few tenths of a point. The gap grows on lopsided markets: try −400/+300 in the calculator.

Things to watch

  • One book's fair is its own opinion. A single book's devigged price is not the market; blend several sharp books for a real fair.
  • Multiplicative overstates longshots on lopsided markets compared with power, Shin and probit.
  • Thin exchange quotes with a wide spread give a noisy fair; our tools never build a fair from a thin quote.

Frequently asked questions

Which devig method is most accurate?
On two-way markets near 50/50 they are practically identical. On lopsided markets, additive, Shin, power and probit generally beat multiplicative, which shifts too much probability onto longshots. Probit is our default. The devig methods guide compares them on real prices.
What is the worst-case column?
For each outcome, the lowest fair probability any of multiplicative, additive or power gives it: a conservative fair for the side you bet. The columns don't add to 100% because each row picks its own method.
Can I devig a three-way soccer market?
Yes. Add the draw as a third outcome; every method handles any number of outcomes.
What is the hold?
The sum of the implied probabilities minus 100%. A −110/−110 market holds 4.76%.

Related calculators

Hold (market vig) calculatorA market's hold, its band (arb, near-arb, low, standard) and fair prices.Expected value (EV) calculatorEV, edge and Kelly from a fair %, fair odds or a two-sided market with the vig removed.Implied probability calculatorBreak-even win % for any price; add the other side for the no-vig fair.Odds converterAmerican, decimal, fractional, probability, HK, Malay, Indonesian.

Learn more

Devig methods compared: multiplicative, additive, power, Shin, probitFive ways to take the vig out of a price, when they agree, when they don't, and which one we use by default.Fair value and devig settings explainedHow the Fair value & filters sheet decides which books build the fair price, how the vig comes off and which rows you see.