No-Vig Calculator

Remove the bookmaker margin from a market to reveal the true fair odds and probabilities — the sharp price behind the line.

e.g. +150 or -110

Bookmaker margin (vig): 4.76%
OutcomeImplied %Fair %Fair odds
Side A52.4%50.0%+100
Side B52.4%50.0%+100

Omenizer devigs the sharpest markets automatically and flags every book priced above the fair line.

See live value bets →

How it works

implied_i = 1 / decimal_odds_i
overround = Σ implied_i           (> 100% — the extra is the vig)
fair_prob_i = implied_i / overround
fair_odds_i = 1 / fair_prob_i

Worked example

A sharp book prices a match −180 / +155. Implied probabilities are 1 ÷ 1.556 = 64.3% and 1 ÷ 2.55 = 39.2%, totalling 103.5% — a 3.5% vig. Divide each by 1.035: fair probabilities become 62.1% and 37.9%, i.e. fair odds of −164 / +164. If another book offers that underdog at +185, you’re getting a price well above the fair line — a positive-EV bet.

Common two-way lines, devigged

MarketTotal impliedVigFair odds
−110 / −110104.8%4.8%+100 / +100
−120 / +100104.5%4.5%−109 / +109
−150 / +130103.5%3.5%−138 / +138
−200 / +170103.7%3.7%−180 / +180
+120 / −140103.8%3.8%+128 / −128
−300 / +240104.4%4.4%−255 / +255

FAQ

What is the vig?
The vig (or juice / margin / overround) is the bookmaker’s built-in edge. If you add up the implied probabilities of every outcome they price, the total is over 100% — that extra is the vig.
How do you remove it?
Divide each outcome’s implied probability by the total (the overround). That rescales them back to 100% and gives the no-vig fair probability; invert it for the fair odds.
Why does the fair price matter?
The no-vig fair price is the market’s best estimate of the true probability. Comparing a book’s price to the no-vig fair price is how you find positive expected value.
Which prices should I devig?
Devig the sharpest, most efficient market you can find (a low-margin book or exchange). The sharper the source, the closer the no-vig line is to the true probability.
How much vig is in a −110/−110 line?
A standard −110 on both sides implies 52.38% + 52.38% = 104.76%, so the vig is about 4.76%. Removing it gives fair odds of +100 (50%) on each side.
What is the multiplicative vs additive method?
This calculator uses the simple (multiplicative) method: divide each implied probability by the total. Some sharps prefer additive or power/Shin methods on lopsided lines, which shift a bit of probability toward favorites. For most 2-way markets the difference is small.
Does devigging work on 3-way markets?
Yes — soccer 1X2, for example. Add all three implied probabilities, then divide each by that total. Switch this tool to 3-way to do it automatically.
Is the no-vig price the same as the true probability?
It’s the market’s best estimate, not a guarantee. A sharp book’s no-vig line is close to true; a soft book’s is noisier. Devig the sharpest source you can.

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Built by the team behind Omenizer’s real-time fair-odds engine — the same devigging and closing-line-value math that powers our live value-bet feed. Last updated July 2026.

Educational tool only. Not betting advice or a guarantee of profit.