No-vig calculator: bookmaker margin and fair odds
Enter the odds of every outcome of one market in any format: 2.10, +110 or 11/10. A soccer 1X2 market needs three prices, a moneyline or a total two.
What the bookmaker margin (vig) is
The vig, or overround, is the markup a bookmaker builds into its odds. Add up the implied probabilities of every outcome (1 / decimal odds) and you get more than 100%; the excess shows how much the book keeps from each bet on average.
The calculator removes the vig proportionally: it divides each implied probability by their sum. That gives fair probabilities that add up to exactly 100% and the fair, no-vig odds.
How to use the no-vig calculator
- Enter the odds of every outcome of one market at one bookmaker: for a 3-way soccer market, home, draw and away.
- Add a row for markets with more outcomes, such as an outright, or remove one you do not need.
- Read the vig of the market and, for each outcome, the implied probability, the fair probability and the no-vig odds.
- Compare the fair odds with prices elsewhere: a price above the fair odds is a value bet if the fair estimate is right.
How to read the result
A vig of 2-3% is typical of the main markets at low-margin books, 5-8% of ordinary moneylines and 1X2 markets, more on exotic markets and live betting. The lower the vig, the closer the odds are to fair.
The fair probability is the book’s own estimate without its markup. The proportional method is exact when the vig is spread evenly; books often load more of it on underdogs, so for long odds the fair probability can come out a little high.
How to calculate the vig by hand
- Example for 2.10, 3.40 and 3.60: S = 0.476 + 0.294 + 0.278 = 1.048.
- Vig: 1 − 1 / 1.048 = 4.6%.
- Fair probability of the home win: 0.476 / 1.048 = 45.4%, no-vig odds 2.10 × 1.048 = 2.20.
What to do next
The BetBuddyRank leaderboard works out the expected hit rate of a priced pick the same way, from the no-vig price: 1 / (odds × 1.05), a typical 5% vig. The tipster index then shows who beats that price over time, not just who backs favourites.
The vig on different markets
| Market | Outcomes | Typical vig | Example odds |
|---|---|---|---|
| Spread or total, main line | 2 | 3-5% | 1.91 / 1.91 (−110 / −110) |
| Moneyline: tennis, NBA, NFL | 2 | 3-6% | 1.50 / 2.55 |
| Soccer 1X2 | 3 | 4-8% | 2.10 / 3.40 / 3.60 |
| Correct score, scorers, futures | many | 15-30% | 6.00 and longer |
FAQ
How do you calculate the bookmaker margin?
Add 1 / odds over every outcome of the market. A sum of 1.05 means a vig of 1 − 1 / 1.05 = 4.8%. Two sides at 1.91 (−110) sum to 1.047, a 4.5% vig.
What is a low vig?
On main markets (spreads, totals, moneylines) 2-3% is low, 4-6% ordinary and 8% or more high. Exotic markets almost always carry more than 10%.
How do I get no-vig odds?
Multiply the odds by the sum of the market’s probabilities. With 2.10, 3.40 and 3.60 the sum is 1.048, so the fair odds of the home win are 2.10 × 1.048 = 2.20.
What is the difference between the vig and the overround?
The overround S shows how much the market adds up to: 1.048 means 104.8%. The vig, 1 − 1 / S, is the share of the money the book keeps on balanced action: 4.6%.
Why does BetBuddyRank multiply the odds by 1.05?
A tipster usually posts only the price of their own pick, not the other sides, so the vig of that exact line is unknown. The leaderboard assumes a typical 5%: the expected hit rate of the pick is 1 / (odds × 1.05).