How the vig (margin) calculator works
Vig, juice or margin is what a bookmaker builds into a market so that the implied probabilities add up to more than 100%. This calculator measures it from the prices, so you can compare how much each bookmaker is charging on the same market.
- Convert each price to an implied probability.
- Add them across all outcomes. The amount over 100% is the margin.
- The payout rate, 1 divided by that total, is the share of stakes the market returns to bettors on average.
Worked example
A two-way market at 1.91 and 1.91.
- Implied probabilities 52.4% and 52.4%, total 104.7%.
- Margin 4.7%; payout rate 95.5%.
On a three-way market include all three prices; margins on football match odds commonly run from 2% at sharp books to 8% or more at recreational ones.
Questions
- Is a lower margin always better for me?
- For the same true chance, yes: lower margin means a bigger price on every outcome. It says nothing about which outcome is worth backing.
- Why do margins differ by market?
- Bookmakers charge more where they are less confident of the true price or expect less sharp money: player props and lower leagues carry more margin than top-flight match odds.
- How is margin different from hold?
- Margin is the overround, the sum of implied probabilities above 100%. Hold is the share of total stakes the bookmaker keeps, 1 minus the payout rate. They describe the same market from two sides.
