No-Vig / Fair Odds Calculator
Enter both sides of a market and this calculator strips out the vig — the bookmaker's built-in margin — to reveal the true implied probability and the fair, no-vig price for each side. Add a draw for 3-way markets.
How the no-vig math works
Every price a sportsbook posts includes a hidden commission. Because of it, the implied probabilities of a market's sides always add up to more than 100%. Removing the vig means redistributing that overage back across the real outcomes.
Take a tennis match at −130 / +110. The favorite's implied probability is 56.5% and the underdog's is 47.6% — a total of 104.1%. That 4.1% is the vig. Divide each side by 104.1% and the fair probabilities become 54.3% and 45.7%, which price out to roughly −119 / +119.
Why the starting line matters
De-vigging only produces a true probability if the line you feed it is sharp. That is why serious bettors devig Pinnacle specifically: it takes the largest bets in the world, does not limit winners, and runs a thin margin, so its prices are the closest thing the market has to the truth. Once you have that fair number, compare it to softer US books to spot +EV bets.
2-way vs. 3-way markets
The method is identical no matter how many outcomes there are. For a soccer match, enter home, draw, and away — the calculator sums all three implied probabilities and divides each by the total. Moneylines, spreads, and totals are 2-way; leave the draw field blank for those.
Devig every market automatically.
Iron Marker removes the vig from the sharp line and compares it to every major US sportsbook in real time, surfacing only the bets that beat fair value — with the Kelly stake already calculated. $39/mo, 7-day free trial.
Start free trialIron Marker is an analytics tool, not a sportsbook, and this calculator is educational — not betting or financial advice. Must be 21+. Problem gambling? Call 1-800-GAMBLER.