To remove vig from odds, convert each price into an implied probability, add those probabilities together, and then divide each one by the total. The result is a no-vig probability that represents the market’s estimated chance after removing the bookmaker’s margin.
What vig means in betting odds
Vig, also called juice or overround, is the bookmaker’s built-in margin. In a fair two-outcome market, the implied probabilities should add up to 100%. With vig included, they add up to more than 100%.
For example, decimal odds of 1.91 on both sides imply:
- 1 ÷ 1.91 = 0.5236, or 52.36% for each outcome
- 52.36% + 52.36% = 104.72%
The extra 4.72 percentage points represent the market overround. This is why simply treating the raw implied probability as the true chance can overstate the likelihood of each outcome.
How to remove vig from two-way odds
The standard no-vig calculation uses this formula:
No-vig probability = implied probability ÷ total implied probability
Using the 1.91 and 1.91 example:
- Raw probability for each side: 1 ÷ 1.91 = 0.5236
- Total raw probability: 0.5236 + 0.5236 = 1.0472
- No-vig probability: 0.5236 ÷ 1.0472 = 0.50
Each outcome has a fair probability of 50%. To convert that probability back to fair decimal odds, use:
Fair decimal odds = 1 ÷ no-vig probability
So, 1 ÷ 0.50 produces fair odds of 2.00 for each side.
Removing vig from unequal two-way prices
The same method works when the odds are different. Suppose a market offers decimal odds of 1.70 on one outcome and 2.20 on the other:
- 1 ÷ 1.70 = 0.5882, or 58.82%
- 1 ÷ 2.20 = 0.4545, or 45.45%
- Total implied probability = 1.0427, or 104.27%
The normalized probabilities are:
- Outcome A: 0.5882 ÷ 1.0427 = 56.42%
- Outcome B: 0.4545 ÷ 1.0427 = 43.58%
The corresponding fair decimal odds are approximately 1.77 and 2.29. These are the prices after allocating the full probability mass back to 100%.
How to remove vig from American odds
American odds must first be converted into implied probability. For positive American odds, use:
Implied probability = 100 ÷ (American odds + 100)
For negative American odds, use:
Implied probability = absolute value of American odds ÷ (absolute value of American odds + 100)
For example, odds of -120 and +110 imply:
- -120: 120 ÷ (120 + 100) = 54.55%
- +110: 100 ÷ (110 + 100) = 47.62%
- Total implied probability = 102.17%
Normalize each figure by dividing it by 1.0217:
- -120 outcome: approximately 53.38% fair probability
- +110 outcome: approximately 46.62% fair probability
After calculating the no-vig probabilities, you can convert them to fair American odds. A probability above 50% uses negative odds, while a probability below 50% uses positive odds:
- For a probability above 50%: American odds = -100 × probability ÷ (1 − probability)
- For a probability below 50%: American odds = 100 × (1 − probability) ÷ probability
How to remove vig from three-way markets
Moneyline markets in sports such as soccer often have three outcomes: home win, draw, and away win. The calculation does not change. Convert all three prices into implied probabilities, add them together, and normalize each one.
For decimal odds of 2.00, 3.40, and 4.00:
- Home win: 1 ÷ 2.00 = 50.00%
- Draw: 1 ÷ 3.40 = 29.41%
- Away win: 1 ÷ 4.00 = 25.00%
- Total implied probability: 104.41%
The no-vig probabilities are approximately:
- Home win: 47.89%
- Draw: 28.17%
- Away win: 23.94%
They add to 100%, apart from rounding. The fair decimal odds are found by taking 1 divided by each normalized probability.
Which no-vig method should you use?
Dividing each implied probability by the total overround is the simplest and most common method for removing bookmaker margin. It assumes the margin is distributed proportionally across the outcomes.
That assumption may not always match how a bookmaker prices a market. In some markets, especially long-shot markets, the bookmaker may apply a larger relative margin to less likely outcomes. Alternative approaches, such as power methods or odds-ratio methods, try to model that uneven distribution. They can produce different fair odds, but they require an additional assumption that cannot be verified from the posted prices alone.
For comparing sportsbook prices, estimating a market consensus, or calculating a basic fair line, proportional normalization is usually the clearest starting point.
Common mistakes when calculating fair odds
- Forgetting to convert odds first: Odds cannot be added directly. Convert every price into an implied probability before removing vig.
- Using percentages without consistent units: Use either decimals such as 0.5236 or percentages such as 52.36%, not a mixture of both.
- Normalizing only one outcome: Every outcome in the same market must be divided by the total implied probability.
- Rounding too early: Keep several decimal places during the calculation and round only the final probability or price.
- Ignoring pushes and void outcomes: Asian handicaps, totals with push possibilities, and derivative markets may need a market-specific treatment.
- Assuming no-vig probability is a guaranteed truth: It is an estimate based on the market prices and the chosen method, not a certainty about the event.
How to use no-vig odds when comparing markets
No-vig odds are useful for comparing a bookmaker’s price with an estimated fair probability. If your own probability estimate is higher than the market’s break-even probability, the price may offer theoretical value. That comparison should account for uncertainty in your estimate, limits, market liquidity, and the possibility that the assumed vig distribution is imperfect.
Removing vig does not create a risk-free bet. It only separates the quoted market prices from their combined margin, helping you compare odds on a more consistent basis. Gambling involves financial risk, so use only money you can afford to lose and follow the rules that apply where you live.
Quick formula reference
For decimal odds d across all outcomes:
Raw implied probability = 1 ÷ d
Overround = sum of all raw implied probabilities
No-vig probability for an outcome = its raw implied probability ÷ overround
Fair decimal odds = 1 ÷ no-vig probability
This process works for two-way and three-way markets and can be adapted to other odds formats after converting them to implied probabilities.