No-Vig Betting Calculator
Fair, margin-free prices and probabilities.
How to Use This Calculator
- Pick the odds format: Decimal, Fractional, or American
- Enter the bookmaker’s odds for each outcome in the event
- Add or drop outcomes as required
- Read the fair (vig-free) odds, fair probabilities, and the bookmaker overround
The overround quantifies the surplus probability the bookmaker embeds as margin.
Formula
Step-by-step process:
- Convert all odds to implied probabilities
- Sum the probabilities (will exceed 100%)
- Divide each probability by the total to get fair probabilities
- Convert fair probabilities back to odds
Overround (Vig) = Total Implied Probability - 100%
Frequently Asked Questions
Vig or juice — what is it?
The vig (vigorish) or juice is the bookmaker’s embedded margin, securing profit irrespective of outcome. It equals the gap between aggregate implied probability and 100%.
Define fair odds.
Fair odds are the odds a zero-margin bookmaker would post. They reflect the true market-implied probability of each outcome.
How much vig is typical?
Sharp bookmakers run roughly 2-3% overround; recreational books often sit at 5-7% or higher. Less vig means better odds for bettors.