No-vig odds calculator and odds converter
Remove the vig
Enter both sides of a prop from a sportsbook, in American odds. The fair probability is what the market thinks each side's real chance is once the book's margin is taken out.
Fair chance, over
53.2%
Fair odds -114
Fair chance, under
46.8%
Fair odds +114
Implied before removing vig: 55.6% and 48.8%.
Book margin (vig): 4.34%
Use the fair chance in the pick'em EV calculator to see whether a pick'em entry with that prop is worth it.
Convert odds
American
-110
Decimal
1.909
Fractional
10/11
Implied probability
52.4%
What “no-vig” means
A sportsbook prices both sides of a market so the implied probabilities add up to more than 100%. The excess is its margin, the vig. A prop at −125 / +105 implies 55.6% and 48.8%, a total of 104.4%. Scaling both sides down so they total 100% gives a fair estimate of 53.2% and 46.8%.
This calculator uses the multiplicative method, which is the most common and works well for evenly priced two-way props. For heavy favorites some bettors prefer power or Shin methods, which shift slightly more of the margin onto the longshot.
Questions
How do I convert American odds to probability?
For negative odds, divide the odds by the odds minus 100: −150 becomes 150 / 250 = 60%. For positive odds, divide 100 by the odds plus 100: +150 becomes 100 / 250 = 40%.
Why use no-vig odds for pick'em?
Pick'em apps pay fixed multipliers regardless of the line's true odds. Comparing a pick'em line to the no-vig probability from sharp sportsbooks tells you whether a pick is more or less likely than the payout assumes.