Remove Vig Calculator

Every time you place a bet, you're paying a tax to the bookmaker. It's baked right into the odds, and most casual bettors never even notice it. This hidden cost is called the vig (short for vigorish), and it's how sportsbooks guarantee themselves a profit regardless of the outcome.

Here's how it works. Take a standard point spread bet: both sides are typically listed at -110. That means you risk $110 to win $100. If the book takes equal action on both sides, they collect $110 from the losers and pay out $100 to the winners—pocketing $10 no matter what happens.

The math gets interesting when you look at implied probabilities. At -110, each side has an implied probability of 52.38%. Add them together and you get 104.76%—that extra 4.76% is the vig. The book is essentially selling you a total probability greater than 100%, which is mathematically impossible for actual outcomes.

When you strip away the vig, you're left with what the bookmaker actually thinks the true probabilities are. This is incredibly valuable information that most bettors ignore.

Let's say you see a moneyline at -150/+130. The favorite's implied probability is 60%, and the underdog's is 43.48%—totaling 103.48%. Remove the vig and you find the book thinks it's really about 58% vs 42%. Now you have the real number to compare against your own analysis.

This also helps you spot which side the book has "shaded." Books often adjust lines based on public betting patterns. If the fair odds suggest a 50/50 game but one side is -120, the book is essentially charging more for the popular side. Sharp bettors look for these discrepancies.

This calculator uses the most common method: proportional distribution. Each outcome's implied probability is divided by the total and multiplied by 100. It's simple, intuitive, and works well for most markets.

Some analysts prefer other methods. The "power method" assumes the vig is distributed based on the odds themselves—longer shots carry more of the margin. The "logarithmic method" uses a different mathematical approach that some argue is more accurate for certain market types.

For practical purposes, the differences between methods are usually small. The proportional method this calculator uses is the industry standard and what most sharp bettors rely on. If you're building complex models, you might experiment with alternatives, but this will serve you well for everyday analysis.

You're looking at an NFL game with these moneyline odds: Chiefs -180, Bengals +155. Your gut says the Bengals have a better shot than the odds suggest. But how much better?

Run it through the calculator. The Chiefs' implied probability is 64.29%, the Bengals' is 39.22%—totaling 103.51%, meaning there's a 3.51% vig. After removing it, the fair probabilities are 62.11% (Chiefs) and 37.89% (Bengals).

Now you know: if you think the Bengals have better than a 37.89% chance of winning, the +155 has value. If your model says they're actually at 42%, you've found a bet where the math is on your side. That's how pros approach betting—not guessing, but comparing their estimates to the true market line.

Once you understand vig, you'll start noticing how much it varies between sportsbooks. That standard -110/-110 line? Some books offer -105/-105, cutting the vig nearly in half. Over hundreds of bets, that difference is enormous.

Reduced juice books like Pinnacle, Circa, and others have built their business model around offering lower margins. They make less per bet but attract higher volume from sharp bettors. If you're serious about long-term profitability, having accounts at reduced juice books is essential.

Props and exotic bets typically carry much higher vig—sometimes 10% or more. This is where sportsbooks make a lot of their money from recreational bettors. If you're betting props, you better have a significant edge to overcome that margin.