Calculators
No-vig calculator: bookmaker margin and fair odds
Enter the price of every outcome. The calculator above shows how much the bookmaker keeps (the vig, or juice) and the fair odds with that margin removed.
More methods
Side ASide BBookmaker’s margin
| Outcome | Chance: price → fair | Fair odds |
|---|---|---|
| Side Aat 1.67 | 60.0% → 58.0% | 1.72−138 |
| Side Bat 2.30 | 43.5% → 42.0% | 2.38+138 |
The prices add up to 103.5% instead of 100%. Bet $100 spread across every outcome so each pays the same, and you get back $96.64 whatever happens: the book keeps $3.36. Proportional takes the margin off each side in proportion to its chance. The usual choice. With Power instead, the fair price of Side B would be 2.40 instead of 2.38.
How it is calculated
Implied chance = 1 ÷ decimal odds1 ÷ 1.67, 1 ÷ 2.30
Sum of implied chances103.48%; margin = sum − 100% = 3.48%
Hold = 1 − 1 ÷ sum3.36% = $3.36 of $100
Proportional: fair chance = implied ÷ sum60.00% ÷ 103.48%, 43.48% ÷ 103.48%
Fair odds = 1 ÷ fair chance1.72, 2.38
Three numbers that measure the margin
Book sum
104.8%Both sides at −110 imply 52.4% each: 52.4% + 52.4% = 104.8%. Without a margin, the sum would be exactly one hundred percent.
Overround
4.76%The amount the implied probabilities add up to above one hundred percent.
Hold
4.55%The bookmaker's share of all money staked. With balanced bets, it keeps $4.55 of every hundred dollars.
Fair price
2.00Remove the margin and each side is 50.0%, or +100 in American odds.
Proportional method: divide by the book sum
fair probability = implied probability ÷ book sum; fair decimal odds = one ÷ fair probability
Example: For example, the favourite: 60.0% ÷ 103.5% = 58.0%, so the fair odds are 1.72 (−138).
Example market before and after
| Step | Favourite | Underdog |
|---|---|---|
| Odds with margin | −150 (1.67) | +130 (2.30) |
| Implied probability | 60.0% | 43.5% |
| Book sum | 103.5% | 103.5% |
| Fair probability | 58.0% | 42.0% |
| Fair odds | −138 (1.72) | +138 (2.38) |
Overround 3.5%, hold 3.36%. Prices are examples only. Switch formats with the odds converter.
Overround vs hold
Overround
- How far the book sum goes over one hundred percent
- Book sum minus one hundred percent
- Standard market: 4.76%
- Example market above: 3.5%
Hold
- Share of all money staked that the bookmaker keeps when bets are balanced
- Overround ÷ book sum
- Standard market: 4.55%
- Balanced bets: $4.55 kept of every hundred dollars staked
- Always a little smaller than the overround
Vig, juice and margin terms
- Vig (vigorish)
- The cost built into the odds. Both sides of an even game pay −110 instead of the fair +100.
- Juice
- Another word for vig, common in North American betting.
- Bookmaker margin
- The general name for the same cost, measured as overround or hold.
- Overround
- How far the book sum goes over one hundred percent.
- Hold
- The share of all money staked that the bookmaker keeps when bets are balanced.
- Implied probability
- The chance a price suggests before the margin is removed: −110 = 52.4%.
- Fair odds
- Odds with the margin removed. The probabilities of all outcomes add up to exactly one hundred percent.
- No-vig odds
- Another name for fair odds.
Questions
What is vig in betting?
Vig, or juice, is the bookmaker's cost built into the odds. Both sides at −110 imply 52.4% each instead of 50.0%. The gap is the vig.
How do you calculate no-vig odds?
Turn each price into an implied probability and add them up. Divide each probability by that total, then convert back to odds. The calculator above does this for two or three outcomes.
Is juice the same as vig?
Yes. Juice, vig, vigorish and bookmaker margin all mean the cost built into the odds. Overround and hold are two ways to measure it.
What can I do with fair odds?
Compare a price you are offered with your own estimate in the expected value calculator. Fair odds are still an estimate. Betting always has a cost, and results vary.
How much does PROLINE keep compared with sportsbooks?
See How much does PROLINE keep? for the margin on PROLINE prices compared with sportsbook prices.