Understanding vig (the juice)
The built-in house edge baked into every bet you place, how to calculate it from the odds yourself, and how to spot when it's higher than it should be on a specific bet.
Vig is the sportsbook's margin, baked directly into the odds on both sides of nearly every bet offered.
Standard -110 pricing means you need to win more than half your bets just to break even, not exactly half.
Vig isn't the same everywhere - it's typically lowest on core lines and highest on parlays, props and futures.
1. What Vig Actually Is
Vig, short for vigorish and also commonly called the juice, is the built-in commission a sportsbook charges on a bet, embedded directly into the odds rather than added as a separate visible fee. It's how sportsbooks generate revenue on their core business: pricing both sides of a bet slightly worse than a mathematically "fair" coin-flip price would suggest, so that the book keeps a small edge regardless of which side of a given bet ultimately wins.
Every bet placed with a licensed sportsbook includes vig in some form, though the exact amount varies meaningfully by market type, covered throughout this guide. Understanding how to spot and calculate it is one of the most practically useful skills a bettor can develop, since it directly explains why a bettor needs to win more than half their bets, not exactly half, just to break even over time.
2. How Vig Gets Built Into A Line
Consider a coin flip with genuinely equal odds on both outcomes: a mathematically fair price for either side would be even money, or +100 in American odds, as covered in our American odds guide. If a sportsbook instead prices both sides of that same coin flip at -110, it has quietly built in a margin: a bettor now needs to risk $110 to win $100 on either side, rather than the fair $100-to-$100 a true coin flip would imply.
This gap between the fair, true-probability price and the actual price offered is the vig. It exists on both sides of the bet simultaneously, which is exactly why a sportsbook doesn't need to guess correctly which side will win - it profits from the built-in margin on the total action taken across both sides, regardless of the actual outcome, assuming its betting volume on each side is reasonably balanced.
3. Standard Vig On A Two-Way Spread: -110/-110
The most common vig level in American sports betting is -110 on both sides of a point spread bet, covered in our moneyline vs. spread vs. total guide. At -110/-110, a bettor needs to risk $110 to win $100 on either side of the spread, which works out to needing to win roughly 52.4% of bets at that price just to break even over time - noticeably more than the 50% a truly fair coin-flip price would require.
| Price | Risk to win $100 | Breakeven win rate |
|---|---|---|
| -110 | $110 | 52.4% |
| -105 | $105 | 51.2% |
| -100 (even) | $100 | 50.0% |
| -120 | $120 | 54.5% |
This single number - 52.4% at standard -110 pricing - is one of the most important reference points in all of sports betting: it's the real bar a bettor needs to clear, not the 50% that an uninformed intuition about a roughly even-money bet might suggest.
Common two-way pricing and breakeven rate
| Two-way price | Implied probability per side | Combined probability | Approx. overround |
|---|---|---|---|
| -105 / -105 | 51.22% | 102.44% | 2.44% |
| -110 / -110 | 52.38% | 104.76% | 4.76% |
| -115 / -115 | 53.49% | 106.98% | 6.98% |
| -120 / -120 | 54.55% | 109.10% | 9.10% |
4. Calculating Implied Probability From Odds
Every American odds price can be converted into an implied probability - what the price itself suggests the true chance of that outcome is, according to the sportsbook. For negative odds, the formula is: implied probability = negative odds ÷ (negative odds + 100), expressed as a percentage. For positive odds, it's: implied probability = 100 ÷ (positive odds + 100).
At +150: 100 ÷ (150 + 100) = 100 ÷ 250 = 40%.
Calculating implied probability for both sides of a bet and adding them together is the most direct way to actually see the vig for yourself, covered next.
5. Why Implied Probabilities Add Up To More Than 100%
On a genuinely fair, vig-free bet, the implied probabilities of every possible outcome should add up to exactly 100% - after all, one of the outcomes has to happen. On an actual sportsbook line, they almost always add up to somewhat more than 100%, and that excess is the vig, expressed as a probability rather than a dollar figure.
This "overround," as it's sometimes called, is a useful quick gut-check for comparing how much margin is built into any given bet: the further the total sits above 100%, the more vig is embedded in that specific price, which is one of the reasons line shopping, covered in our line shopping guide, can meaningfully improve results over time.
6. Vig On Moneylines
Moneyline vig works slightly differently than a standard two-way spread because the two sides usually aren't priced symmetrically - a favorite might be -180 while the underdog is +155, rather than matching numbers on both sides. Calculating the implied probability of each side separately and adding them together still reveals the same underlying overround, even though the individual numbers look less obviously matched than a simple -110/-110 spread.
7. Vig On Totals
Total (over/under) bets, covered in our moneyline vs. spread vs. total guide, are typically priced with vig similar to a standard spread - commonly -110 on both the over and the under - following the same overround logic covered in section 5. A sportsbook adjusts the actual total number itself, rather than the odds, to reflect where it expects roughly balanced betting volume on both sides, while keeping the vig on either side of that number fairly consistent.
8. Vig On Three-Way Markets (Soccer)
Sports with a genuine three-way outcome, most notably soccer's win/draw/loss market, spread vig across three separate prices rather than two, and the overround calculation works identically - add up the implied probability of all three outcomes, and the amount above 100% is the vig. Because there are three outcomes instead of two to price, the total vig on a three-way market is often somewhat higher in raw percentage-point terms than a comparable two-way market, even when each individual price looks reasonable in isolation.
9. Vig On Parlays: How It Compounds
Parlays, covered in our parlays and same-game parlays guide, combine the vig from every individual leg into the overall payout, meaning the effective house margin on a parlay compounds across each leg rather than staying flat. A four-leg parlay built from bets each carrying standard -110 vig will have a meaningfully higher effective overall margin than any single leg would carry on its own, which is part of why parlays are mathematically tougher to beat over time than an equivalent set of straight bets, even though a well-constructed parlay can still be a reasonable, fun way to bet in moderation.
10. Vig On Props And Futures: Why It's Often Higher
Player props and futures markets, covered in our props guide and futures guide, frequently carry higher vig than a core spread, moneyline, or total, often because these markets see lower overall betting volume and require more manual oversight from a sportsbook's risk team, both of which tend to justify a wider built-in margin from the book's perspective. A bettor comparing a straightforward -110 spread against a prop priced closer to -130 on both sides is looking at a genuinely higher hurdle to clear profitably, even if the specific prop itself is well-analyzed.
11. How Vig Varies Between Sportsbooks
Different sportsbooks set their own vig levels independently, meaning the exact same bet can carry noticeably different margin at one book compared to another - one operator's standard spread pricing might run -110/-110 while another consistently runs closer to -105/-105 on comparable markets. This is one of the clearest, most direct reasons line shopping matters, since consistently betting at a book with lower standard vig produces a real, compounding difference in long-run results even without any change in picking ability.
12. Reduced Vig Promotions And Loyalty Tiers
Some sportsbooks offer reduced-vig promotions, either as a standing feature on certain markets or as a loyalty-tier benefit for high-volume customers, temporarily or permanently lowering the standard margin on qualifying bets. These programs are worth factoring into an overall assessment of which sportsbook offers the best long-term value, alongside the sign-up bonus terms covered in our bonus terms guide.
12.5 Comparing Vig To Other Everyday Transaction Costs
It can help to think of vig the same way you'd think of a foreign currency exchange fee or a payment processing charge: a standard, disclosed cost of doing business with a company that needs a way to profit from the transactions it facilitates. The difference between a sportsbook and a currency exchange counter is mainly that the sportsbook's margin is expressed in odds rather than a flat percentage fee, which is exactly why converting odds into implied probability, as covered in section 4, is such a useful habit - it translates an unfamiliar-looking price into the same kind of "what am I actually paying" figure you'd expect from any other transaction.
13. Why Vig Exists: The Business Behind It
Sportsbooks are commercial businesses that need a sustainable revenue model, and vig is the primary mechanism that provides one. Rather than needing to correctly predict game outcomes themselves, a well-run sportsbook aims to set prices that attract roughly balanced betting volume on both sides of a market, profiting from the built-in margin on the total action regardless of which side ultimately wins - a fundamentally different business model than trying to "beat" bettors through superior predictions.
Understanding this helps explain sportsbook behavior that can otherwise seem confusing, like a line moving specifically in response to lopsided betting volume rather than new information about the game itself, covered further in our live betting and futures guides.
14. How Vig Affects Your Long-Term Breakeven Win Rate
Because of vig, a bettor's actual required win rate to break even over time is always somewhat higher than the naive 50% a coin-flip framing might suggest, and the exact number depends on the specific vig level of the bets being placed. At standard -110 pricing, that breakeven point is roughly 52.4%, as covered in section 3; at the higher vig common on some props and parlays, the breakeven win rate climbs further still, which is why consistently betting at lower vig, through line shopping and reduced-juice programs, provides a genuine, quantifiable improvement to a bettor's long-term prospects, independent of picking skill.
15. Common Vig Misunderstandings
Assuming a 50% win rate is enough. At standard -110 pricing, breakeven is closer to 52.4%, as covered in section 3 - a 50% win rate at that price is actually a small long-term loss.
Treating all vig as identical. Vig varies meaningfully by market type and by sportsbook, as covered in sections 9, 10, and 11 - a parlay or prop is rarely priced at the same effective margin as a core spread.
Believing vig means a bet is "rigged." Vig is a transparent, standard business margin built into the price, not a sign of manipulation - it's disclosed directly in the odds themselves for anyone who calculates implied probability.
Ignoring vig entirely when comparing bets. Two bets with the same likely outcome can still represent different real value once the specific vig on each is accounted for.
16. Worked Examples, Start To Finish
Example 1 - Calculating vig on a standard spread. Both sides of a spread are priced at -110. Implied probability on each: 52.4%. Combined: 104.8%. The vig is 4.8 percentage points.
Example 2 - Calculating vig on an uneven moneyline. Favorite -170 (63.0%), underdog +145 (40.8%). Combined: 103.8%. The vig here is 3.8 percentage points - slightly lower than the standard spread example.
Example 3 - Comparing vig across two sportsbooks on the same bet. Book A prices a spread at -110/-110 (104.8% combined); Book B prices the identical spread at -105/-105 (102.4% combined). Book B carries noticeably less built-in margin on the exact same bet.
Example 4 - Recognizing higher vig on a prop. A player prop is priced at -130 on both over and under. Implied probability on each: 56.5%. Combined: 113%, meaningfully higher vig than a standard game line.
17. Frequently Asked Questions
What's the difference between vig and juice?
Nothing - they're two names for the same thing: the built-in margin a sportsbook charges, embedded in the odds.
What win rate do I actually need to break even?
It depends on the specific vig level of the bets you're placing. At standard -110 pricing, it's roughly 52.4%, as covered in section 3.
Can I avoid vig entirely?
Not really - nearly all sportsbook bets include some level of built-in margin. You can reduce how much you pay through line shopping and reduced-vig promotions, covered in sections 11 and 12.
Why is vig higher on parlays and props than on spreads?
Parlay vig compounds across every leg, as covered in section 9, and prop vig is often set higher due to lower volume and more manual pricing oversight, as covered in section 10.
How do I calculate vig myself on any given bet?
Convert each side's odds to implied probability using the formulas in section 4, add them together, and anything above 100% is the vig, as covered in section 5.
18. Quick-Reference Glossary
- BREAKEVEN WIN RATE
- The percentage of bets a bettor needs to win at a given price just to break even over time, accounting for vig.
- IMPLIED PROBABILITY
- The win probability suggested by a given set of odds, calculated directly from the price itself.
- OVERROUND
- The amount by which the combined implied probability of all outcomes in a market exceeds 100%, representing the vig.
- REDUCED VIG
- A promotion or loyalty benefit that lowers a sportsbook's standard built-in margin on qualifying bets.
- VIG (VIGORISH) / JUICE
- The built-in commission a sportsbook charges on a bet, embedded directly into the odds on both sides.