No-Vig Calculator: Find the True Odds
Strip the bookmaker margin from any betting line to reveal the true implied probability and fair odds. Works with 2-way and 3-way markets.
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This calculator uses the proportional (multiplicative) method to remove vig — each side's implied probability is divided by the total overround. This is the most common approach but assumes the vig is distributed proportionally. For heavily lopsided markets, power or Shin methods may be more accurate.
What Is the Vig (Juice)?
The vig — also called juice, margin, or overround — is the bookmaker's built-in profit margin on every betting line. It's why the odds on both sides of a bet don't add up to a fair 100% probability.
For example, a standard -110/-110 line implies each side has a 52.4% chance of winning. That's 104.8% total — the extra 4.8% is the vig. In a truly fair market, even-money odds would be +100/+100 (50%/50%).
The no-vig calculator above strips this margin to show you what the bookmaker actually thinks the true probabilities are before they add their cut.
Why This Matters
Knowing the true (no-vig) odds helps you:
Compare your estimate to the market's — if your model says a team has a 55% chance of winning but the no-vig probability is 60%, the market disagrees with you
Find value bets — use the fair probability in the EV Calculator to check if your estimated edge is real
Compare bookmakers — the one with lower vig offers better value on the same event
Understand the cost of betting — the vig is the price you pay to place a bet, just like a commission
How to Use This Calculator
Select your odds format — American, Decimal, or Fractional
Enter odds for both sides (or all three for soccer/draw markets)
Read the results — you'll see each side's raw implied probability, the total overround (vig), the true fair probability, and what the fair odds would be without the margin
The Math Behind It
For a 2-way market with decimal odds D₁ and D₂:
Implied probability: P₁ = 1/D₁, P₂ = 1/D₂
Total overround: P₁ + P₂ (will be > 1.00)
Fair probability: P₁_fair = P₁ / (P₁ + P₂)
Fair decimal odds: D₁_fair = 1 / P₁_fair
The same logic extends to 3-way markets — just divide each side's implied probability by the total.
Frequently Asked Questions
What is a typical vig?
US sportsbooks typically charge 4-5% vig on standard lines (-110/-110 = 4.55%). Sharp books may offer 2-3%. Recreational books and exotic bets can carry 10-20%+ vig.
Is lower vig always better?
Yes — lower vig means you keep more of your winnings. Over hundreds of bets, the difference between 4% vig and 2% vig is significant. This is why line shopping matters.
How does the vig relate to the house edge?
The vig IS the house edge for sports betting. A 4.55% vig on a -110/-110 line means the bookmaker expects to keep about 4.55 cents of every dollar wagered — similar to how a 2.7% house edge works in European roulette.
Can I use no-vig odds to find +EV bets?
Yes — that's the primary use case. If you estimate a team's true probability is higher than the no-vig fair probability, the bet has positive expected value. Use the EV Calculator to quantify the edge.
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About the author
Provably Fair & Payments Writer
Devon covers the technical side of crypto: how blockchains reach consensus, provably fair verification, seeds and hashes, and how deposits and withdrawals actually move — from casino approval to network confirmations.