How to Remove Vig From Odds | No-Vig Probability Formula

Removing the vig from odds means taking the bookmaker’s margin out of a market so you can estimate the fair probability of each outcome. The standard method is to convert every price into an implied probability, add those probabilities together, and then divide each one by the total.

This process is also called de-vigging odds, removing the juice, or calculating no-vig probabilities. It is useful when comparing sportsbook prices, estimating a market’s consensus view, or deciding whether your own probability is higher than the fair market probability.

What the vig means in betting odds

The vig, short for vigorish, is the bookmaker’s built-in margin. In a two-outcome market, the implied probabilities usually add up to more than 100%. That excess is the overround or bookmaker hold.

For example, suppose a tennis match has these decimal odds:

Player A: 1.80
Player B: 2.10

Convert each decimal price into an implied probability using:

Implied probability = 1 ÷ decimal odds

Player A: 1 ÷ 1.80 = 0.5556, or 55.56%
Player B: 1 ÷ 2.10 = 0.4762, or 47.62%

The total is 103.18%. The market therefore has an estimated overround of 3.18%. If the probabilities added up to exactly 100%, there would be no vig in the market.

How to remove vig from decimal odds

Once you have the implied probabilities, normalize them so that they total 100%. The formula is:

No-vig probability = implied probability ÷ total implied probability

Using the tennis example:

Player A: 55.56% ÷ 103.18% = 53.85%
Player B: 47.62% ÷ 103.18% = 46.15%

These are the market’s estimated fair probabilities after removing the bookmaker margin. To convert a no-vig probability back into fair decimal odds, use:

Fair decimal odds = 1 ÷ no-vig probability

Player A: 1 ÷ 0.5385 = 1.86
Player B: 1 ÷ 0.4615 = 2.17

The fair prices are higher than the listed bookmaker odds because the bookmaker’s margin has been removed.

Removing vig from American odds

American odds must first be converted into implied probabilities. For positive American odds, use:

Probability = 100 ÷ (American odds + 100)

For negative American odds, use:

Probability = absolute value of American odds ÷ (absolute value of American odds + 100)

For example, odds of -120 and +105 produce these raw implied probabilities:

-120: 120 ÷ 220 = 54.55%
+105: 100 ÷ 205 = 48.78%

The combined probability is 103.33%. Normalize each figure by dividing it by 103.33%:

-120 outcome: 54.55% ÷ 103.33% = 52.79%
+105 outcome: 48.78% ÷ 103.33% = 47.21%

The same normalization method works for fractional odds and markets with more than two outcomes. For fractional odds, first add one to the fraction to get decimal odds. In a football three-way market, convert the home, draw, and away prices separately, add the three implied probabilities, and divide each probability by that total.

Using no-vig odds to assess value

No-vig probabilities give you a cleaner reference point than the posted prices, but they are not guaranteed to be the true probabilities. The market can be wrong, and removing the vig does not account for differences in sportsbook limits, betting volume, sharp action, or the way a bookmaker distributes its margin across outcomes.

To compare your own estimate with the market, first express your opinion as a probability. If you estimate an outcome at 56% and the no-vig market probability is 53.85%, your estimate is higher. The fair odds associated with your estimate are:

1 ÷ 0.56 = 1.79

You would then compare 1.79 with the available bookmaker price, while also considering limits, account restrictions, market liquidity, and the possibility that your estimate is uncertain. A difference between your probability and the no-vig figure is only a potential edge, not a guaranteed profit.

Important limitations of the calculation

Margin may not be distributed evenly: a simple proportional adjustment assumes the vig is allocated in proportion to each implied probability.
Three-way and prop markets need care: removing the overround does not correct for possible bookmaker bias toward popular outcomes or selected player props.
Prices should be from the same market: combining odds from different books can create an artificial market unless the lines refer to identical rules and settlement conditions.
Use current prices: injuries, lineups, weather, and betting activity can change the probability represented by a market.

The core calculation remains straightforward: convert odds to implied probabilities, add them to find the overround, divide each probability by the total, and convert the result back to fair odds if needed.