No-vig (fair odds) calculator

A book's two prices add up to more than 100%. The extra is the vig. Enter both sides to see the fair chance of each and how much the book keeps. Free, no sign-up, nothing leaves your browser.

Worked example

Over -115 and Under -105 imply 53.5% and 51.2%, a total of 104.7%. Dividing each by that total gives a fair chance of 51.1% for the Over (-104) and 48.9% for the Under (+104). The book's margin is 4.7%.

How it works

The calculator turns each price into an implied probability, adds the two, and divides each side by the total so they sum to 100%. The amount over 100% is the margin. This spreads the margin across both sides in proportion; other methods exist and give slightly different fair prices, especially on lopsided markets.

ArchivePicks uses the same removal of the margin when it compares one book's price with the other books on the board, so a price can be judged against a margin-free view of the market.

Frequently asked questions

What does no-vig mean?

No-vig, or fair, odds are a market's prices with the book's margin removed, so the two sides add up to exactly 100%.

What is the vig, hold or juice?

It is the margin built into a book's prices. If a market's two implied probabilities add up to 104.8%, the margin is 4.8%.

Are no-vig odds the true odds?

No. They are a fair-looking version of one book's own prices. They depend on how the margin is shared between the sides, and the true chance of the outcome is still unknown.

Can I use this on prediction market prices?

Yes, if you have both sides. Convert each price to American odds first, or use the odds converter, then enter them here.

Related

• Implied probability calculator
• Expected value (EV) calculator
• Odds converter: American, decimal and implied probability
• All odds calculators
• No-vig in the Glossary
• Player Prop Lines Explained: Over, Under, Half-Points and Prices

For information only. ArchivePicks does not take bets and does not tell you which side to take.