No-Vig Fair Odds Calculator
Calculate fair odds by removing the bookmaker vig. Convert posted betting lines to true probability and no-juice odds for sharp betting analysis.
Side 1 (Favorite/Team A)
Side 2 (Underdog/Team B)
About This Calculator
No-vig (or "fair") odds represent what betting lines would look like without the bookmaker's built-in profit margin. Understanding and calculating these true probabilities is essential for serious sports bettors who want to find value and build profitable betting models.
Why No-Vig Odds Matter: Every sportsbook builds a profit margin (vig/juice) into their odds. Standard -110/-110 lines on a 50/50 proposition give the book ~4.55% edge. By removing the vig, you can see the market's true implied probabilities and identify where you might have an edge.
How It Works:
- Convert odds to implied probabilities
- Total will exceed 100% (the excess is the vig)
- Normalize probabilities to sum to exactly 100%
- Convert back to odds format
Applications:
- Building betting models with accurate baselines
- Identifying value when comparing to your own projections
- Comparing lines across sportsbooks
- Understanding true market consensus
Example: Posted odds: -150/+130 (implied: 60%/43.5% = 103.5%) Fair odds: -138/+138 (true: 58%/42% = 100%)
The book is charging ~3.5% juice. Your job is to find spots where you think the true probability differs from these no-vig lines.
For vig analysis, see our Vig Calculator. For odds conversions, try our Odds Converter.
How to Use the No-Vig Fair Odds Calculator
- 1Select your preferred odds format (American, Decimal, or Fractional).
- 2Enter the posted odds for Side 1 (favorite or Team A).
- 3Enter the posted odds for Side 2 (underdog or Team B).
- 4Choose a de-vigging method (Multiplicative is standard).
- 5Review the calculated fair (no-vig) odds.
- 6Check the true probabilities for each side.
- 7Note the edge calculation at posted odds.
- 8Use fair odds to compare against your own projections.
- 9Shop other sportsbooks for lines better than fair.
- 10Incorporate no-vig lines into your betting models.
Understanding the Vig
The vig (vigorish/juice) is how sportsbooks guarantee profit.
How Vig Works
In a fair market with two 50% outcomes:
- Fair odds: +100/+100 (2.00/2.00 decimal)
- Implied probability: 50% + 50% = 100%
With vig:
- Posted odds: -110/-110 (1.91/1.91 decimal)
- Implied probability: 52.4% + 52.4% = 104.8%
- Vig: 4.8%
The book pays out less than fair odds on both sides.
Calculating Vig
Formula: Vig = (Total Implied Probability - 100%)
Example: -150/+130
- Side 1 implied: 150/(150+100) = 60.0%
- Side 2 implied: 100/(130+100) = 43.5%
- Total: 103.5%
- Vig: 3.5%
Vig Levels by Market
| Market Type | Typical Vig |
|---|---|
| NFL/NBA spreads | 4-5% |
| Moneylines | 5-8% |
| Player props | 8-15% |
| Parlays | 15-30%+ |
| Live betting | 6-12% |
Lower vig = better value for bettors.
De-Vigging Methods
Several mathematical methods exist for removing vig.
Multiplicative (Standard)
The most common and widely used method.
Formula: True Probability = Implied Probability / Total Implied Probability
Example:
- Implied: 60% and 43.5% (total: 103.5%)
- True Side 1: 60% / 103.5% = 58.0%
- True Side 2: 43.5% / 103.5% = 42.0%
Best for: Most markets, especially balanced lines.
Additive
Removes equal vig from both sides.
Formula: True Probability = Implied Probability - (Vig / 2)
Example:
- Vig: 3.5% → Remove 1.75% from each
- True Side 1: 60% - 1.75% = 58.25%
- True Side 2: 43.5% - 1.75% = 41.75%
Best for: Markets where you believe vig is applied equally.
Power Method
Uses logarithmic adjustment based on odds ratio.
Best for: Markets with moderate favorite/underdog spread.
Shin Method
Developed by economist Hyun Song Shin for horse racing.
Removes more vig from the underdog side, reflecting that:
- Favorites attract more recreational money
- Books shade toward favorites
- Underdogs may have more value
Best for: Markets with significant favorites (-300 or beyond).
Finding Betting Value
No-vig odds help identify positive expected value bets.
The Value Formula
Edge = Your Probability × Payout - 1
Or equivalently: Edge = Your Probability - True Market Probability
Example: Finding Value
Market: Team A vs Team B
- Posted odds: -150/+130
- No-vig true probability: 58%/42%
Your analysis suggests Team B has 47% chance (not 42%).
Your edge on Team B:
- Market says: 42%
- You believe: 47%
- Edge: +5%
At +130 odds (2.30 decimal): EV = 0.47 × 2.30 - 1 = +8.1%
This is a value bet worth making.
Comparing to Other Books
Use no-vig as your benchmark:
- Fair odds for Team B: +138
- Book A offers: +125 (worse than fair)
- Book B offers: +142 (better than fair)
Book B gives you positive edge vs. the market!
Building a Model
Step 1: Calculate no-vig odds from sharp books (Pinnacle, Circa) Step 2: Use these as your baseline probabilities Step 3: Adjust based on your own analysis Step 4: Bet when your probability exceeds the market by enough to overcome vig
Sharp vs. Square Markets
Not all odds are created equal.
Sharp Books
Books like Pinnacle and Circa:
- Lowest vig (2-3% on major sports)
- Accept large bets
- Move lines based on sharp action
- Closest to "true" market odds
Use sharp books to derive no-vig baseline.
Square Books
Recreational-focused books:
- Higher vig (5-8%+)
- Limit winning bettors
- Lines may lag sharp books
- Offer promotions to attract bets
Compare to sharp no-vig to find value at square books.
Line Movement and CLV
Closing Line Value (CLV): The difference between your bet price and closing price.
- Sharp action moves lines
- Closing line is most accurate
- Consistent positive CLV = skill
- No-vig closing line is ultimate benchmark
Market Efficiency
Major markets (NFL, NBA, etc.):
- Very efficient
- Hard to beat
- Small edges if any
Smaller markets (college, props, etc.):
- Less efficient
- More potential value
- But higher vig to overcome
Two-Way vs. Multi-Way Markets
De-vigging works differently for different market types.
Two-Way Markets
Standard head-to-head or over/under:
- Enter both odds
- De-vig as shown
- Clear true probabilities
Three-Way Markets (Soccer, etc.)
Home/Draw/Away markets:
- Enter all three odds
- Same multiplicative formula
- Probabilities sum to 100%
Example: Soccer Match
- Home: +150 (40%)
- Draw: +220 (31.3%)
- Away: +180 (35.7%)
- Total: 107%
- True: 37.4% / 29.3% / 33.4%
Moneylines with Draw
Some sports allow ties:
- Must account for draw probability
- De-vig all three outcomes
- Or use separate "moneyline" without draw
Props and Totals
Same principles apply:
- Over/Under are two-way markets
- Player props are two-way
- Higher vig means more to remove
- Value harder to find in high-vig markets
Advanced Concepts
Taking no-vig analysis further.
Combining Multiple Books
Wisdom of crowds approach:
- Get odds from multiple sharp books
- De-vig each one
- Average the true probabilities
- Result: robust market consensus
Pinnacle as Benchmark
Why Pinnacle is the gold standard:
- Lowest vig in industry
- Highest limits
- Doesn't ban winners
- Most efficient market
Pinnacle no-vig = best proxy for true odds.
Half-Point Buying
In NFL/NBA spreads:
- Calculate no-vig probability at each half-point
- Understand value of buying/selling points
- Key numbers (3, 7 in NFL) have different value
Market-Implied Probabilities in Modeling
Use no-vig as features:
- Input to machine learning models
- Combine with your own factors
- Bet when model differs significantly from market
The Limits of No-Vig
No-vig odds assume:
- Market is efficient
- True probability exists
- Vig is applied proportionally
Reality:
- Markets can be wrong
- Different books have different information
- Vig distribution varies by market type
No-vig is a tool, not the truth.
Pro Tips
- 💡Use sharp book odds (Pinnacle, Circa) when calculating no-vig baselines.
- 💡Multiplicative de-vigging is standard and works for most markets.
- 💡Compare your probability estimates to no-vig lines to find value.
- 💡Both sides at posted odds have negative edge - that's the vig.
- 💡Shop lines at multiple books to find odds better than fair.
- 💡Higher vig markets require larger edges to be profitable.
- 💡Track your CLV vs. no-vig closing lines to measure skill.
- 💡Use no-vig probabilities as inputs to your betting models.
- 💡The Shin method works better for heavy favorite markets.
- 💡No-vig is a tool for analysis, not a guarantee of true probability.
- 💡Line movement toward your side is usually a good sign.
- 💡Consider transaction costs (time, multiple accounts) in value calculations.
Frequently Asked Questions
No-vig odds are betting lines with the bookmaker's profit margin removed. They represent the market's true implied probabilities. For example, -110/-110 odds imply 52.4% each side (104.8% total). Removing the 4.8% vig gives 50%/50% true probability, which would be +100/+100 in fair odds.
