vigorish calculator

Enter two market odds to estimate sportsbook hold (vig), no-vig probabilities, and fair odds. Supports American odds (e.g., -110, +145) and decimal odds (e.g., 1.91, 2.45).

What Is Vigorish?

Vigorish (often called vig, juice, or hold) is the built-in commission a sportsbook charges by shading odds away from true probability. In a perfectly fair two-outcome market, implied probabilities would add up to 100%. In real markets, they usually add up to more than 100%—that extra percentage is the bookmaker's edge.

If you only look at raw odds and skip vig removal, you can easily overestimate value and make bad bets. That is why a vigorish calculator is a foundational tool for sports bettors, market analysts, and anyone comparing lines across books.

How to Use This Vigorish Calculator

Enter odds for two opposing outcomes (Team A / Team B, Over / Under, Yes / No).
Click Calculate Vig.
Review:
- Implied probabilities from listed odds
- Total overround and sportsbook hold
- No-vig (fair) probabilities
- No-vig fair odds in decimal and American format

How the Math Works

1) Convert each odd into implied probability

For American odds:

Positive odds (+X): implied probability = 100 / (X + 100)
Negative odds (-X): implied probability = X / (X + 100), where X is absolute value

For decimal odds:

implied probability = 1 / decimal_odds

2) Find overround and vig

overround = p1 + p2
vig (hold) = overround - 1

If overround is 1.045, then vig is 0.045, or 4.5%.

3) Remove vig to get fair probabilities

no_vig_p1 = p1 / (p1 + p2)
no_vig_p2 = p2 / (p1 + p2)

Then convert those no-vig probabilities back into fair odds. These fair odds are what you compare to your own model or projection.

Example: Why -110 / -110 Is Not 50/50

At -110 on both sides, each implied probability is about 52.38%. Added together, that is 104.76%. The extra 4.76% is the book’s margin. After removing vig, each side returns to a true 50% fair probability.

That gap is exactly why bettors who ignore vig can think they have an edge when they do not.

Why No-Vig Probabilities Matter

Line shopping: Compare fair pricing across sportsbooks more accurately.
Model validation: Compare your projected probabilities to no-vig market probabilities, not juiced ones.
Expected value: EV calculations become cleaner and more realistic when the vig is stripped out.
Risk management: Helps avoid overbetting weak edges that disappear once juice is accounted for.

Common Mistakes Bettors Make

Using listed implied probabilities as if they are true probabilities.
Comparing your model to one side of the market without normalizing both sides first.
Assuming all books have the same hold percentage.
Ignoring the difference between American and decimal formatting.

FAQ

Is a lower vig always better?

Generally yes. Lower hold means prices are closer to fair value, which improves long-term expected returns.

What if the calculator shows a negative hold?

That means implied probabilities sum to less than 100%, which may indicate an arbitrage opportunity or stale line data.

Can I use this for props and futures?

Yes for two-way prop markets. For multi-outcome markets (like outright winners), you would need a multi-way overround calculator.

Final Thought

Vig is small on a single bet and massive over thousands of bets. If you are serious about betting performance, removing vigorish before making pricing decisions is non-negotiable.

vigorish calculator