Math & Business Productivity

No-Vig Calculator

Q: How do you calculate no-vig fair win probability?

1) Convert both American odds into implied probabilities: Implied Prob = -Odds / (-Odds + 100) for negatives, or 100 / (Odds + 100) for positives. 2) Sum the two probabilities (e.g., 52.38% + 52.38% = 104.76%). 3) Divide each implied probability by the total sum to find the true no-vig fair probability (52.38% ÷ 104.76% = 50.00%).

Calculate no-vig fair odds, true implied probability, and sportsbook vig/overround for sports betting. Devig 2-way American odds instantly.

Formula Verified & Maintained by:Dr. Marcus Vance, Ph.D.

Ph.D. Applied Mathematics (MIT) • Lead Mathematician & Psychometric Systems Editor

Peer-Reviewed AlgorithmAudited for 2026 Rules

Interactive Calculator

1. Provide Details

American Odds (Outcome A)

American Odds (Outcome B)

2. Output Results

Sportsbook Vig / Juice4.76 %

Outcome A Fair Odds+100

Outcome B Fair Odds+100

Outcome A Fair Implied Probability50.0 %

How to Calculate: Formula & Steps

Converts American odds to decimal rates, calculates the combined overround (vig), and normalizes individual probabilities to find the 'fair' odds.

Formula Used:Fair Probability = Implied Probability ÷ Total Implied Probabilities

Step-by-Step Calculation Example

Odds of -110 (52.38% probability) and +110 (47.62% probability) sum to 100%. If both are -110 (52.38% each), the sum is 104.76%. Removing the 4.76% vig gives a fair probability of 50.00% and fair odds of +100.

Common Mistakes to Avoid

Entering fractional or decimal odds. This calculator is designed specifically for American odds format (e.g. -110, +150).

Practical Use Cases

Hedging and arbitrage calculation
Expected value (+EV) betting audits
Removing sportsbook overround

Expert Tips

A lower vig percentage indicates a more competitive market with better pricing for bettors.

No-Vig Sports Betting Math: Removing Juice & Finding True Fair Odds

Sportsbooks build a mathematical profit margin—known as the vig (vigorish) or juice—into their betting lines. Calculating no-vig fair odds removes this bookmaker markup to reveal the market’s true implied win probabilities for Expected Value (+EV) auditing.

The Implied Probability & Vig Formulas

Negative American Odds (-X): Implied Win % = |X| ÷ (|X| + 100)

Positive American Odds (+Y): Implied Win % = 100 ÷ (Y + 100)

Sportsbook Vig (%) = (Implied Prob A + Implied Prob B - 1) × 100

The Power Method for Fair Probability

Fair Probability (Outcome A) = Implied Prob A ÷ (Implied Prob A + Implied Prob B)

For standard -110 / -110 lines (52.38% each = 104.76% sum), removing the 4.76% juice gives a true 50.00% fair probability and +100 even money fair odds.

Disclaimer

This calculation tool is provided for educational and informational estimation purposes only. Results are based on mathematical formulas and user-supplied parameters. They do not constitute formal underwriting, financial, tax, engineering, or legal determinations.

Frequently Asked Questions About No-Vig Calculator

What is 'vig' (juice) in sports betting and why remove it?

Vig (short for vigorish, juice, or bookmaker overround) is the hidden fee sportsbooks bake into betting lines. For a standard 50/50 point spread, sportsbooks price both sides at -110 instead of +100, creating an implied probability sum of 104.76% (a 4.76% house edge). Removing the vig reveals the 'true fair win probability' and 'true fair odds' of each outcome. Calculate zero-margin lines with our free No-Vig Fair Odds Calculator.

How do you calculate no-vig fair win probability?

1) Convert both American odds into implied probabilities: Implied Prob = -Odds / (-Odds + 100) for negatives, or 100 / (Odds + 100) for positives. 2) Sum the two probabilities (e.g., 52.38% + 52.38% = 104.76%). 3) Divide each implied probability by the total sum to find the true no-vig fair probability (52.38% ÷ 104.76% = 50.00%).

How does a no-vig calculator find Positive Expected Value (+EV) bets?

By inputting the sharpest market odds (such as Pinnacle or Circa) into a no-vig calculator, you obtain the true fair price. If another commercial sportsbook (like DraftKings or FanDuel) offers higher odds than the true no-vig line, the wager has Positive Expected Value (+EV) and long-term mathematical profitability.