Market Margin Calculator
Calculate the bookmaker's margin (overround) on any betting market with 2 or more selections.
Bookmaker Margin
4.76%
Total Implied
104.76%
Fair Probabilities (No Margin):
The bookmaker keeps approximately 4.55% of every dollar wagered on this market.
What is Bookmaker Margin?
The bookmaker margin (also called overround, vig, or juice) is how sportsbooks guarantee profit. In a fair market, all implied probabilities sum to exactly 100%. Sportsbooks inflate these probabilities so they sum to more than 100%.
For example, a standard -110/-110 market has implied probabilities of 52.38% each, totaling 104.76%. The 4.76% over 100% is the margin. Lower margins mean better value for bettors.
Sharp sportsbooks typically have margins of 2-4% on main markets, while recreational books may have 6-10%+. Shopping for the best lines across multiple books helps minimize the margin you pay.
This calculator is for informational and educational purposes only. Results should be verified with your sportsbook before placing any wagers. All betting carries risk. Full Disclaimer
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Responsible Gambling
Gambling should be entertaining, not a way to make money. Only bet what you can afford to lose, and never chase your losses.
- Betting more than you can afford to lose
- Chasing losses with bigger bets
- Lying to others about gambling habits