No-Vig Calculator
A posted price includes the book's margin. Strip it out and you get the probability the market actually believes — the number every edge is measured against.
This market is priced at 103.50%, so the book is holding 3.50%. Removing it puts the fair price at -164 / +164.
The posted odds are the market's opinion.
The two-way market
Most common. Removes vig proportionally — the side with more juice loses more.
What the book is charging
Anything over 100% is the book's margin. That excess is what devigging removes.
The fair price — Multiplicative
Every method, side by side
The methods disagree most on lopsided markets. Where they spread widely, treat any single fair price as an estimate rather than a fact.
A devigged price is only as honest as the book you took it from. Strip the vig off a soft book and you get that book's opinion with the margin removed — not the market's. Anchor to a sharp book, and prefer the method the market you're pricing actually behaves like.