Vig (Overround) Calculator

Quick Facts

  • Computes sportsbook margin from odds.
  • Inputs: 2–3 outcomes in any odds format.
  • Outputs: vig % and market probability sum.

How to use

Steps

Enter prices for each outcome. The tool converts to implied probabilities and reports the amount above 100% as the vig.

Formula & definitions

Formula: Vig (%) = (Σ implied probabilities − 1) × 100

Vig / Overround
Margin included in market prices.
Implied Probability
1 / decimal odds.

Vig Calculator (Sportsbook Margin)

0.00%

What is Vig (Sportsbook Margin)?

Vig—short for "vigorish"—is the built-in margin that sportsbooks add to their odds to guarantee a profit regardless of the outcome. The lower the vig, the better value for you!

How Does the Vig Calculator Work?

  • Enter odds for two or three outcomes (Decimal, American, or Fractional).
  • The calculator shows you the total implied probability—minus 100% is the "vig" or edge.
  • Works for 2-way (e.g., Tennis) and 3-way (e.g., Soccer) markets.
  • Spot high-margin (bad value) lines instantly.

Why Does Vig Matter?

  1. Understanding vig helps you find the best value—lower vig = higher potential return!
  2. Compare sportsbooks and always bet where the vig is lowest.
  3. Use our No-Vig Odds Calculator for true fair odds.
  4. Gain an edge and improve your long-term results.
Tip: For +EV betting, always calculate the vig—and shop around for the lowest margin!
See also: EV Calculator