Tool
Sportsbook Overround & No-Vig Calculator
Measure book percentage and proportionally normalized no-vig probabilities for a complete market.
Quick answer
Enter decimal odds for every mutually exclusive outcome in the same market. The tool reports overround and normalized probabilities; it does not claim those normalized values are objectively true probabilities.
Remove displayed sportsbook margin
Enter all mutually exclusive market outcomes.
Supported market sizes
The comma-separated input can handle two-way, three-way and larger complete markets.
Formula
Raw implied probability = 1/decimal odds. No-vig probability = raw probability ÷ sum of all raw probabilities.
Critical condition
Do not use only a subset of outcomes from a larger market.
Related reading
Responsible gambling: Gambling involves financial risk. Never chase losses or gamble with money needed for essentials. Eligibility and legal age vary by jurisdiction.