Vig/Juice Calculator
Calculate the vig (vigorish/juice) on sports betting odds. Find the bookmaker's edge, true odds, expected value, and compare lines across sportsbooks.
Side 1 (Team A / Over / Yes)
Side 2 (Team B / Under / No)
Related Calculators
About This Calculator
The vigorish (vig), also known as juice or the overround, is the bookmaker's built-in commission on every bet. Understanding the vig is crucial for sports bettors because it directly impacts your expected value and long-term profitability. This calculator reveals the hidden cost in betting lines.
What is the Vig? When a sportsbook offers -110 on both sides of a bet, they're not offering fair odds. The vig is the difference between what you'd get at true (fair) odds and what the book actually pays. On -110/-110 lines, the book takes about 4.55% regardless of the outcome.
Why the Vig Matters:
- It represents the guaranteed profit margin for sportsbooks
- Higher vig = worse value for bettors
- Even winning bettors lose money if vig is too high
- Shopping for lower vig lines is one of few edges available
The Math Behind It: For a standard -110/-110 line:
- Implied probability: 52.4% + 52.4% = 104.8%
- True probability: 50% + 50% = 100%
- Vig: 104.8% - 100% = 4.8% (or 4.55% as edge per dollar)
How to Use This Information:
- Compare vig across sportsbooks
- Calculate true probabilities for modeling
- Find the best value lines
- Understand your expected loss on each bet
This calculator helps you see through the lines. For converting odds formats, try our Odds Converter.
How to Use the Vig/Juice Calculator
- 1Select your odds format (American, Decimal, or Fractional).
- 2Enter the odds for Side 1 (Team A, Over, Yes, etc.).
- 3Enter the odds for Side 2 (Team B, Under, No, etc.).
- 4Optionally change the bet amount for EV calculations.
- 5Review the calculated vig percentage.
- 6Check the true (fair) probabilities for each side.
- 7Compare posted odds to fair no-vig odds.
- 8Use fair odds to evaluate if you have an edge.
- 9Shop other sportsbooks for lower vig alternatives.
- 10Factor vig into your betting models and bankroll strategy.
Understanding the Vig
How bookmakers build their edge into every line.
The Basic Concept
In a fair market with two equally likely outcomes:
- Fair odds: +100 / +100 (even money)
- Implied probability: 50% / 50% = 100% total
With vig:
- Posted odds: -110 / -110
- Implied probability: 52.4% / 52.4% = 104.8% total
- Overround: 4.8%
The extra 4.8% represents the bookmaker's built-in profit.
How Books Make Money
Scenario: $1,000 bet on each side at -110
| Outcome | Book Pays | Book Keeps |
|---|---|---|
| Side 1 wins | $1,909.09 | $90.91 |
| Side 2 wins | $1,909.09 | $90.91 |
The book profits ~$90 regardless of outcome (4.55% of $2,000).
Standard Vig Levels
| Line Type | Typical Vig |
|---|---|
| NFL/NBA spreads | 4-5% |
| Moneylines (favorite) | 5-10% |
| Totals | 4-5% |
| Player props | 8-15% |
| Parlays | 15-30%+ |
| Live betting | 6-12% |
Why Vig Varies
Lower vig on:
- High-volume markets (NFL, NBA)
- Reduced juice books
- Sharp money markets
Higher vig on:
- Exotic bets and props
- Small college/international sports
- Live/in-play betting
Calculating True Probabilities
Stripping the vig to find fair market odds.
The Formula
Implied Probability from American Odds:
For negative odds: Probability = |Odds| / (|Odds| + 100) For positive odds: Probability = 100 / (Odds + 100)
Example: -150 / +130 line
- Side 1 (-150): 150 / (150 + 100) = 60%
- Side 2 (+130): 100 / (130 + 100) = 43.5%
- Total: 103.5% (vig = 3.5%)
Removing the Vig
True probability = Implied probability / Total implied probability
- True Side 1: 60% / 103.5% = 58.0%
- True Side 2: 43.5% / 103.5% = 42.0%
- Check: 58% + 42% = 100% ✓
Fair Odds from True Probability
American odds from probability:
If probability ≥ 50%: Odds = -(Prob × 100) / (1 - Prob) If probability < 50%: Odds = (1 - Prob) × 100 / Prob
For our example:
- Fair Side 1: -(58 × 100) / 42 = -138
- Fair Side 2: 42 × 100 / 58 = +72
Compare: Posted (-150/+130) vs Fair (-138/+138) The book is charging you worse odds than fair!
Shopping for Value
Using vig analysis to find better lines.
Why Line Shopping Matters
Different books offer different lines. A 2-point vig difference can mean:
- $20 saved per $1,000 wagered
- 0.5%+ improvement in expected value
- Thousands saved over a betting career
Example: Line Comparison
| Sportsbook | Team A | Team B | Total Vig |
|---|---|---|---|
| Book A | -110 | -110 | 4.55% |
| Book B | -108 | -108 | 3.77% |
| Book C | -105 | -105 | 2.44% |
On a $1,000 bet, the difference:
- Book A: Expect to lose $45.50
- Book C: Expect to lose $24.40
- Savings: $21.10 per bet
Best Practices
1. Use multiple books Open accounts at 3-5 sportsbooks minimum.
2. Check lines before betting Compare every bet across books.
3. Know the standard -110 is "standard" but many books offer -105 or better on major sports.
4. Track your edge Calculate expected value for every bet considering vig.
Reduced Juice Books
Some sportsbooks specialize in low vig:
- -105 standard lines (vs -110)
- Competitive moneylines
- Lower prop vig
Even small improvements compound significantly over time.
Expected Value and the Vig
How vig impacts your betting profitability.
Expected Value Formula
EV = (Probability of Win × Profit) - (Probability of Loss × Stake)
Example: Standard -110 Bet
Betting $100 on a 50/50 proposition at -110:
- Win: Profit $90.91
- Lose: Lose $100
- True probability: 50% each
EV = (0.50 × $90.91) - (0.50 × $100) EV = $45.45 - $50.00 = -$4.55
You lose $4.55 expected on every $100 bet!
Breaking Even
To break even at -110 odds, you need to win: 110 / (110 + 100) = 52.4%
Not 50% - you need to beat the vig!
Finding +EV Bets
For a bet to have positive expected value: Your estimated probability > Break-even probability
If you think Team A has a 55% chance at -110:
- Break-even: 52.4%
- Your edge: 55% - 52.4% = 2.6%
- EV = (0.55 × $90.91) - (0.45 × $100) = $5.00
This is a +$5 EV bet per $100.
Impact on Bankroll
Over 1,000 bets at -110 with true 50% win rate:
- Expected loss: $4,550
- This is GUARANTEED to happen long-term
Sharp bettors overcome vig with edges. Recreational bettors pay it as entertainment cost.
Vig in Different Bet Types
How bookmakers vary vig across markets.
Point Spreads
Most competitive market with lowest vig.
- Standard: -110 / -110 (4.55%)
- Best available: -105 / -105 (2.44%)
- Worst: -115 / -105 (6.00%)
Moneylines
Vig increases with favorite probability.
| Matchup Type | Typical Vig |
|---|---|
| Pick 'em | 4-5% |
| Small favorite (-150) | 5-6% |
| Moderate (-300) | 6-8% |
| Heavy (-500+) | 8-12% |
Heavy favorites have terrible value due to high vig.
Totals (Over/Under)
Similar to spreads.
- Standard: -110 / -110
- Can find -105 at low-vig books
- Alt lines have higher vig
Player Props
Highest vig category.
- Standard: -115 / -105 or worse
- Some books: -120 / +100
- Vig: 8-15%
Parlays
The real vig is in the math, not the odds.
Even at "true odds" on each leg, parlays multiply risk. Add standard vig on each leg, and expected loss is massive.
| Legs | True Payout | Typical Payout | Hidden Vig |
|---|---|---|---|
| 2 | 3:1 | 2.6:1 | 13% |
| 3 | 7:1 | 6:1 | 14% |
| 4 | 15:1 | 10:1 | 33% |
Avoid parlays for serious bankroll growth.
Odds Formats Explained
Understanding different ways to express betting odds.
American Odds
Standard in US sportsbooks.
Negative odds (favorites): How much to bet to win $100
- -150 means bet $150 to win $100
- -200 means bet $200 to win $100
Positive odds (underdogs): How much you win on $100 bet
- +150 means win $150 on $100 bet
- +200 means win $200 on $100 bet
Decimal Odds
Common in Europe, Australia, Canada.
Format: Total return on $1 bet (including stake)
- 1.50 = Win $0.50 on $1 bet (get back $1.50)
- 2.50 = Win $1.50 on $1 bet (get back $2.50)
Conversion to probability: Probability = 1 / Decimal odds
Fractional Odds
Traditional UK format.
Format: Profit / Stake
- 3/1 = Win $3 for every $1 bet
- 1/2 = Win $1 for every $2 bet
- 10/11 = Win $10 for every $11 bet
Conversion to probability: Probability = Denominator / (Numerator + Denominator)
Quick Conversion Table
| American | Decimal | Fractional | Implied % |
|---|---|---|---|
| -200 | 1.50 | 1/2 | 66.7% |
| -150 | 1.67 | 2/3 | 60.0% |
| -110 | 1.91 | 10/11 | 52.4% |
| +100 | 2.00 | 1/1 | 50.0% |
| +150 | 2.50 | 3/2 | 40.0% |
| +200 | 3.00 | 2/1 | 33.3% |
Pro Tips
- 💡Always calculate the vig before placing a bet.
- 💡Shop lines across multiple sportsbooks for every bet.
- 💡Avoid props with vig above 10% unless you have strong edge.
- 💡Use reduced juice books for your main action.
- 💡Remember: -110 requires 52.4% win rate to break even.
- 💡Convert odds to implied probability to understand true cost.
- 💡Parlays compound vig - stick to straight bets for value.
- 💡Heavy favorites often have the worst vig - be careful.
- 💡Track your CLV (closing line value) to measure betting skill.
- 💡Use no-vig odds in your betting models for accurate probabilities.
- 💡Lower vig is one of few consistent edges available to bettors.
- 💡Entertainment value has a cost - that's the vig you're paying.
Frequently Asked Questions
The vig (vigorish), also called juice or overround, is the bookmaker's built-in commission on bets. It's the reason implied probabilities sum to more than 100%. On standard -110/-110 lines, the vig is about 4.55%, meaning the book keeps $4.55 of every $100 wagered regardless of outcome.
