What Is Vig and How Does It Work in Sports Betting?

The vig is one of the most important aspects of betting on sports that most sports bettors completely overlook. I want to make sure that you don’t make the same mistake so many others have made, so, in this article, I’ll tell you everything you need to know about the vig.

First, I’ll explain what the vig in sports betting is, tell you how it works, then dive into the vig’s impacts and how it should affect your sports betting strategy.

The vig—short for vigorish, and also known as juice or the margin—is the fee sportsbooks charge for their services. The vig ensures that sportsbooks actually make money. It is incorporated into every single bet.

Every sportsbook has a different vig level, but most Canadian betting sites effectively charge a vig of around 4.76% on standard bets with -110 odds. This can vary depending on the type of bet, odds offered, and the sportsbook’s pricing strategy.. I’ll break this down and tell you more about the finer points of the vig below.

The vig works because it is built into the betting odds. When you place a bet, you are predicting an outcome. That outcome has an implied probability. True odds would represent that implied probability accurately.

For example, if the implied probability were 50% chance, the odds would be -100. You would wager $100 to win $100 back. All the money that comes in from losing wagers would go back out to winners. The vig changes the odds so that the sportsbook is guaranteed to keep some of the money no matter the outcome.

Basic Example

Odds of 110 mean that you have to wager $110 to win $100. This implies an approximate 4.76% vig, which is standard at most legal sports betting sites. The $10 difference between your wager and your potential profit isn’t pure profit for the sportsbook. Instead, it reflects how the odds are adjusted in the sportsbook’s favor.

If both sides of a bet receive equal action, the sportsbook earns roughly $4.76 on every $220 wagered (that is, $110 on each side).

Why Sportsbooks Use the Vig

Asking why sportsbooks use the vig is like asking why movie theaters make you pay for movie tickets. The vig is how sportsbooks make money. Without taking a cut of the money that comes in, they wouldn’t be able to make a profit. If there’s no way to make a profit, companies don’t have an incentive to offer a service. In other words, the vig is why sportsbooks exist at all. If there wasn’t a profit motive, no one would offer bets. 

Calculating the vig goes back to the topic of implied probability I mentioned earlier. Basically, you need to calculate the implied probabilities of each outcome, add them together, and subtract 100% from it. Whatever’s left is the vig. You can do this easily with online tools and calculators like odds converters, but it’s good to know how to calculate the vig without these tools so that you have a more hands-on understanding of what the vig is.

First, we’ll start with the odds. Canadian sportsbooks use the American odds format with positive and negative numbers (e.g., -110 and +120). Use these formulas to convert American odds into their implied probabilities:

• For negative odds, use: Implied Probability = (−Odds) / (−Odds + 100) × 100
• For positive odds ,  Implied Probability = (100 / (Positive Odds + 100)) × 100

Once you have the implied probabilities, add them together and subtract 100 to calculate the vig.

Standard -110 Odds

Say that you are betting on a totals bet, both the over and under will normally have -110 odds since they theoretically are both just as likely to occur. Here’s how to calculate the vig of -110 odds in this situation:

• Over (-110): (110/(110+100)) x 100 = 52.38%
• Under (-110): (110/(110+100)) x 100 = 52.38%

Final Vig Calculation = (52.38% + 52.38%) - 100 = 4.76%

Different Odds and Vig Impact

-110 odds is the standard betting odds and vig for totals and spreads betting in Canada. Moneyline bets can be different though since the chance of one team beating another is rarely 50%. Let’s use -120 odds for Team A and +105 odds for Team B and calculate vig like you would for moneyline bets:

• Team A (-120): (120/(120+100)) x 100 = 54.55%
• Team B (+105): (100/(105+100)) x 100 = 48.78%

Final Vig Calculation = ((54.55%+48.78%)-100 = 3.33%

Here’s a quick summary table to help visualize how vig varies depending on the odds and bet type:

Vig Calculators and Tools 

As you can see from my examples above, it’s not hard to calculate the vig. It can be a bit tedious though if you are shopping around or placing a lot of bets, so I recommend taking advantage of online vig calculators and other sports betting tools. They are very reliable and really cut down on the amount of time you need to calculate vig.

The vig is not a bad thing and a totally normal part of the sports betting world. That said, it can really have a huge impact on your long-term profits.

The best way to illustrate this is to imagine you place 10 $110 wagers on a bet with -110 odds. Each wager would pay out $100 if you win. So, if you 50% of the time—which is what you’d expect from the implied probability—you will get $500 back. However, you will lose $550, which means a net loss of $50 even though you theoretically broke even.

The more bets you place, the more extreme this phenomenon becomes. The same is true for the vig. Even small vig percentages can eat into your profits, so make sure you stick with sportsbooks that have a fair vig and to shop around for value bets.

As I’ll explain in detail later, you can never avoid the vig completely. However, you can do things to reduce the effect of the vig over time. Here are the two most effective strategies to minimise the impact of the vig.

Line Shopping

Line shopping is the process of comparing odds, spreads, and listed lines between sportsbooks. The vig is baked into all sports betting odds, but it’s based on the line, so finding a better line for the bet you want to place makes the bet more valuable to you even if the vig is the same.

Let’s say you’re betting on the Chiefs and you think they will win:

• Sportsbook A has the Chiefs -3.5
• Sportsbook B has the Chiefs -2.5

Sportsbook B is the better sportsbook for you because the Chiefs only need to win by 3 points for your bet to cash out instead of four points like at Sportsbook A.

Promotions and Reduced Juice

Sportsbooks know smart bettors understand the vig. To encourage more wagering, they do things to minimise the impact of the vig like free bet offers, reduced juice promos, and other sportsbook bonuses. Cashed Sportsbook, for example, already has low vig, but it also has a wide variety of boosted bets and other promos to make its odds even better.

The amount of vig varies slightly between sports and types of bets. Here is the standard vig for a few common betting markets.

Moneyline Bets

Moneyline bets have the widest variance of vig depending on how evenly matched the teams are and where the money is going. Using the odds and converting them into implied probabilities will tell you the true vig. Generally speaking, though, moneyline bets typically have vig under 5%.

Point Spreads

The vig for points spread bets is almost always around 5%. This comes out to -110 odds for both the underdog and the favourite. -110 odds ensures that the sportsbook takes in $10 in profit, which is $5 for each side of the bet.

Totals

Totals bets typically have a vig around 5% and –110 odds for both the over and under wagers. The logic here is similar to the reason for points spread bets having -110 odds. The sportsbook gets a cut regardless of the outcome.

Parlays and Futures

Futures and parlays have higher vig than other bets since the vig is compounded and because there is more uncertainty in the market. Vig for these bet can be as high as 20% or more. 

Understanding the vig and how it works won’t guarantee that you win your bets, but it will give you an edge compared to sports bettors who don't understand it. For one, understanding that sportsbooks take a cut of every bet and knowing how much they take allows you to better manage your bankroll.

You can also use your knowledge of the vig to evaluate which sportsbooks are worth playing at and to evaluate odds so that you can identify which sites actually offer value to their bettors.

The vig is one of the most hotly-debated topics in all of sports betting. Part of the reason for this is because there are so many myths about it. Let’s cut through the noise and address some of these myths head-on.

The Vig is a Hidden Fee

Many believe the vig is some sneaky hidden cost sportsbooks use to rip you off after you win. In reality, it’s embedded into every bet you place. It’s not some hidden fee tacked on at the end, it’s just the way sportsbooks ensure that they make a profit.

Higher Vig Always Means Worse Bets

Generally speaking, I would recommend avoiding sportsbooks with a high vig. That said, a high vig doesn’t always mean worse bets. You should instead focus on the value of each individual bet. If a low-vig sportsbook offers -200 for a bet, but a high-vig sportsbook has it listed at -120, the high-vig sportsbook has the more valuable bet.

You Can Easily Avoid the Vig

When I explain what the vig is to someone, the first thing they ask me is how to avoid it. The simple fact is that you can’t. Every legal sportsbook has a vig because it’s how they make money. You can theoretically “beat the vig” through smart bets and shopping around for the best odds, but you can never avoid it.