No-Vig Calculator: true odds without the bookmaker's margin
Every sportsbook builds a margin into its odds. That margin is how they guarantee a profit regardless of the outcome. You see 1.90 on both sides of a coin-flip market, but the fair price would be 2.00 and 2.00. This calculator strips away that markup and shows what the odds would look like without the house cut.
Here's a quick example. A bookmaker offers 1.85 on the home team and 2.05 on the away side. Add the inverse values: 1/1.85 + 1/2.05 = 0.540 + 0.488 = 1.028. That's 102.8%, which means the book is charging a 2.8% margin on this market. The calculator removes it and reveals fair odds of roughly 1.90 and 2.11, with true probabilities of 52.6% and 47.4%.
This matters for two reasons. First, you get to see how the bookmaker actually rates each side without the commission on top. Second, you can compare margins across sportsbooks. Pinnacle typically holds 2-3% on major events, while smaller books often take 6-8%. The lower the margin, the better the deal for the bettor.
Switch between the two-outcome and three-outcome modes depending on the sport. Tennis and basketball are two-way markets. Football with the draw option is three-way. Odds can be entered in decimal, American, or fractional format.