No-vig calculator: devig odds to fair odds
Every sportsbook price has the book’s margin, the vig, built in, so the implied probabilities of the two sides add up to more than 100%. Devigging strips that margin out and leaves fair odds: the book’s own estimate of each side’s chance of winning.
Fair odds from a sharp book are the usual yardstick for whether a price elsewhere is worth betting. Enter both sides of a market and pick a method, and the calculator shows the hold, the fair odds for each side and the probability behind them.
Free, no account needed. Everything is worked out in your browser and nothing you type is saved.
How to use the no-vig calculator
- 1Enter the odds for both sides of one market from the same sportsbook, ideally a sharp one.
- 2Pick a devig method. Multiplicative is the common default; the others split the margin differently between favorite and underdog.
- 3Read Fair Odds 1 and 2 and the fair probability under each. Hold % is the margin that was removed.
- 4Take the fair odds to the expected value calculator to see whether a price at another book beats them.
Worked example: -150 / +130
A sportsbook prices a game at -150 for the favorite and +130 for the underdog.
- Implied probability -150 / +130
- 60.00% / 43.48%
- Hold
- 3.48%
- Fair probability (multiplicative)
- 57.98% / 42.02%
- Fair odds (multiplicative)
- -138 / +138
- Fair odds (additive, power or Shin)
- -140 / +140
The multiplicative method scales both probabilities down by the same factor, so the favorite comes out at -138 and the underdog at +138. The other three methods take more of the margin out of the underdog and land at -140 / +140. An underdog price above those numbers at another book is positive EV by this book’s estimate.
Frequently asked questions
What does no-vig mean?
No-vig odds are a price with the sportsbook’s margin removed, so the implied probabilities of all outcomes add up to exactly 100%. They are the book’s estimate of the fair price.
Which devig method should I use?
Multiplicative is the usual default and works well for markets close to even. When one side is a heavy favorite, power or Shin usually fits better, because bettors overpay for longshots and those methods take more of the margin out of the underdog.
Which sportsbook should I devig?
A sharp book with low margins and high limits, such as Pinnacle, or a betting exchange. Their prices move on sharp money, so their fair odds are the closest thing to a true line. Devigging a recreational book mostly tells you how that book shaded its own line.
How do I turn fair odds into expected value?
Compare them with a price you can bet. In the example the underdog’s fair probability is 42.02% (+138). If another book offers +150, a $100 bet has an expected value of $5.04, or 5.04%. The expected value calculator does this for you.
Free now, free for good
Every BreadSync calculator is free to use without an account, and that is not changing. They work on the odds you type in.
BreadSync Pro devigs sharp books across every market and flags the prices elsewhere that beat fair value, live.
Related calculators
- Expected Value CalculatorCompare the odds you can bet with fair no-vig odds to see what a bet is worth on average.
- Kelly Criterion CalculatorSize a bet from your edge and bankroll, with full, half and quarter Kelly.
- Low Hold CalculatorSee the hold on any market and size both sides for cheap betting volume, including split legs.
- Odds ConverterConvert between American, decimal and fractional odds and implied probability.
21+. Worked examples are illustrative and use made-up prices; real odds change constantly. Calculator results are estimates for information only, not betting advice or a guarantee of profit. BreadSync is not a sportsbook and does not accept wagers. If gambling stops being fun, call 1-800-GAMBLER.