Sportsbook odds include a margin, often called the vig or juice: add up the implied chances of every outcome and you get more than 100%. This no-vig calculator strips that margin out to show the fair odds and the true implied chance of each outcome, so you can compare a sportsbook line with a prediction market price on equal terms.
Enter the odds for every outcome in the market. The calculator converts each to an implied chance, measures the margin (how far the total is above 100%), and scales the chances down proportionally to remove it. Fair odds are what the price would be with no margin.
How it works
- Convert each price to an implied chance. −110 in American odds is 110 ÷ 210 = 52.4%. Decimal 2.50 is 1 ÷ 2.50 = 40%.
- Add them up. Two sides at −110 total 104.8%. The extra 4.8% is the margin.
- Scale them back to 100%. Divide each chance by the total. 52.4% ÷ 104.8% = 50%, so the fair price of each side is even money (+100, decimal 2.00).
This is the proportional (multiplicative) method, the most common way to remove the margin. Other methods spread the margin differently between favourites and long shots, which can give slightly different fair prices for lopsided markets.
Worked examples
| Odds entered | Total implied | Margin | Fair chances | Fair odds |
|---|---|---|---|---|
| −110 / −110 | 104.8% | 4.8% | 50.0% / 50.0% | +100 / +100 |
| 1.50 / 2.60 (decimal) | 105.1% | 5.1% | 63.4% / 36.6% | 1.58 / 2.73 |
Comparing with prediction markets
Prediction market prices don’t have a margin built in the same way: a Yes share at 52¢ and a No share at 48¢ already add up to $1, and the cost of trading shows up as the bid-ask spread and a separate fee instead. So the fair, no-vig sportsbook chance is the right number to compare with a prediction market price. If a sportsbook’s no-vig chance is 50% and a market trades at 45¢, the market is cheaper for that side, before fees.
To convert a single price between formats, use our odds converter. For prices on both big prediction markets side by side, see the price-gap scanner.
FAQ
What does “no-vig” mean?
How much vig does −110 / −110 have?
Can I use this for markets with more than two outcomes?
Is this the same as Novig?
Related: Odds converter · Spreads, liquidity and limit orders · Prediction markets vs sports betting