How to read a no-vig line (and calculate fair odds)

A no-vig line is a betting market with the sportsbook's margin (the vig) removed, so the two sides' probabilities add up to exactly 100%. The no-vig price on each side is called the fair odds. To get there, convert both sides' odds to implied probabilities, add them up, and divide each side by that total. This is the multiplicative method.

Quick example (made-up numbers): a market of -200 / +170 has implied probabilities of 66.67% and 37.04%, which add up to 103.70%. Dividing each side by 103.70% gives fair probabilities of 64.29% and 35.71%, which are fair odds of -180.0 / +180.0.

Decimal odds show the total return per $1 staked, stake included.

• Positive American odds: decimal = 1 + odds ÷ 100. Example: +170 → 1 + 1.70 = 2.70
• Negative American odds: decimal = 1 + 100 ÷ |odds|. Example: -200 → 1 + 0.50 = 1.50

The implied probability is how often a bet has to win for its price to break even.

Implied probability = 1 ÷ decimal odds

• +170 → 1 ÷ 2.70 = 37.04%
• -200 → 1 ÷ 1.50 = 66.67%

Shortcut for negative odds: |odds| ÷ (|odds| + 100). For -110, that is 110 ÷ 210 = 52.38%.

Add the two implied probabilities. On a market with vig, the total is above 100%. Two numbers describe that margin.

• Overround is the sum of the implied probabilities minus 100%. It measures the market's margin. This page uses "overround" whenever it talks about the size of a market's margin.
• Hold is 1 − (1 ÷ sum). It is the share of total money bet that the book keeps if it takes balanced action on both sides.

The two numbers describe the same margin, so they move together, but the hold is always a little smaller than the overround.

Real example: Georgia State vs. James Madison (Pinnacle, LineGoat's October 16, 2026 scan). Pinnacle priced Georgia State at +306 and James Madison at -391.

• Georgia State +306 = 4.06 decimal, implied probability 24.63%
• James Madison -391 = 1.2558 decimal, implied probability 79.63%
• Sum = 104.26%
• Overround = 104.26% − 100% = 4.26%
• Hold = 1 − 1 ÷ 1.0426 = 4.09%

More markets (made-up numbers except the first row):

A lower overround means a cheaper market to bet into.

Divide each side's implied probability by the sum of both. The results add up to exactly 100%. These are the fair (no-vig) probabilities.

Fair probability = side's implied probability ÷ sum of both implied probabilities

Using the -200 / +170 example (made-up numbers):

• Favorite: 66.67% ÷ 103.70% = 64.29%
• Underdog: 37.04% ÷ 103.70% = 35.71%
• Check: 64.29% + 35.71% = 100.00%

The multiplicative method takes the margin off each side in proportion to its implied probability. The favorite carries more implied probability, so more of the vig comes off the favorite in absolute terms (2.38 percentage points) than off the underdog (1.32 points).

First get fair decimal odds, then convert to American.

• Fair decimal odds = 1 ÷ fair probability
• If fair decimal odds are 2.00 or higher: American = +(decimal − 1) × 100
• If fair decimal odds are below 2.00: American = −100 ÷ (decimal − 1)

Worked through (made-up numbers):

• Underdog: 1 ÷ 0.3571 = 2.80 decimal → (2.80 − 1) × 100 = +180.0
• Favorite: 1 ÷ 0.6429 = 1.5556 decimal → −100 ÷ 0.5556 = -180.0

Worked through (real Georgia State market): 24.63% ÷ 104.26% = 23.62% fair probability → 1 ÷ 0.2362 = 4.233 decimal → +323.3 for Georgia State and -323.3 for James Madison.

A fair two-way market is symmetrical in American odds: the favorite's fair price and the underdog's fair price have the same number with opposite signs. A -110 / -110 market devigs to +100.0 / +100.0, which is even money.

To check your own numbers, use the no-vig calculator on FreeBettingTools, our sister site. It uses the same multiplicative method. Its "Vig (hold)" figure is the hold, not the overround (4.1% for the Georgia State market). It also rounds fair odds to whole numbers, so it shows +323 where LineGoat shows +323.3.

A no-vig calculation only works when both prices describe the same bet from opposite sides.

• Moneyline: Team A to win and Team B to win, from the same book at the same time.
• Spread: both sides on the same number, such as Team A -3.5 and Team B +3.5. If the sides are on different numbers, they are different bets.
• Total: Over and Under on the same number, such as Over 44.5 and Under 44.5.
• Both sides are required. You cannot remove the vig from one price on its own, because the overround only shows up when the two sides are added together.
• Three-way markets (for example soccer win/draw/win) need all three prices. Add all three implied probabilities and divide each by that total.
• Use one book. Mixing the favorite's price from one book with the underdog's price from another does not measure either book's overround.

The fair odds you get are only as good as the market you devig. A soft or stale market gives a less useful fair price.

Multiplicative is the most common devig method, but it is not the only one. Researchers describe at least three others:

• Additive: subtracts an equal share of the overround from each side.
• Power: raises each implied probability to the same power, chosen so the results add to 100%.
• Shin: models the book as pricing against a share of better-informed bettors. On a two-way market, Shin gives the same result as the additive method.

On an even market the methods agree: -110 / -110 devigs to +100.0 / +100.0 under all four. They split apart as the gap between favorite and underdog grows. Additive, Shin and power all take more of the vig off the underdog than multiplicative does, so multiplicative gives the longshot a higher fair probability and shorter fair odds than the other three.

Comparison (made-up numbers except the last row):

Percentages are the underdog's fair probability.

For the -500 / +380 market, the underdog's fair odds run from +400.0 (multiplicative) to +454.1 (power). A +430 price at another book beats the multiplicative fair line and falls short of the additive, Shin and power fair lines. The method choice can decide whether a longshot looks +EV.

One study compared these methods on 14,925 men's tennis matches plus greyhound and horse racing data. In the tennis data, the power method had the best or equal-best result on every measure and the multiplicative method had the worst (Clarke, Kovalchik and Ingram, American Journal of Sports Science, 2017, doi:10.11648/j.ajss.20170506.12). That study did not cover US team sports.

LineGoat's Edge of the Day scan removes the vig from Pinnacle's two-sided price with the multiplicative method described in Step 4. The scan only uses markets with exactly two outcomes, so both sides are always available. The fair probability is converted back to American odds and shown to one decimal as "Fair odds (no-vig)" on the Edge of the Day card.

A US sportsbook price counts as an edge when its EV against that multiplicative fair probability is between 1% and 12%, at a price between -400 and +500. The same multiplicative method is applied to Pinnacle's closing line for closing line value.

Because the multiplicative method gives longshots shorter fair odds than additive, Shin or power do, LineGoat's scan can rate longshot underdogs as better value than those methods would. On the October 16 Georgia State market, multiplicative put Georgia State's fair odds at +323.3; additive and Shin put them at +344.5, and power at +357.0. LineGoat discloses this on How Edge of the Day works.

• EV: comparing a fair probability with another book's price gives expected value. LineGoat's method is on How Edge of the Day works.
• CLV: devigging the closing line gives the benchmark for closing line value. See What is closing line value (CLV)?

Fair odds are an estimate of the true probability. A price better than fair odds can still lose, and no devig method predicts a single result.

What does no-vig mean in sports betting?

No-vig means the sportsbook's margin has been removed from the odds, so both sides' probabilities add up to 100%. The resulting prices are called fair odds.

How do you calculate no-vig odds?

Convert both sides to implied probabilities (1 ÷ decimal odds), add them, and divide each side by the total. Then convert each fair probability back to odds with 1 ÷ fair probability.

What are the fair odds on a -110 / -110 line?

The fair odds are +100.0 on both sides (even money). Each side implies 52.38%, the total is 104.76%, and each side devigs to 50%.

What is the difference between overround and hold?

Overround is the sum of the implied probabilities minus 100%, which was 4.26% on Pinnacle's Georgia State market. Hold is 1 − 1 ÷ sum, which was 4.09% on the same market. A calculator's "Vig (hold)" figure is the hold.

Which devig method does LineGoat use?

LineGoat's scan uses the multiplicative (proportional) method on Pinnacle's two-sided prices. The details are in "How LineGoat's scan removes the vig" above.

Can I devig one side of a market?

No. Removing the vig needs both sides of the same market, because the overround only appears when the two implied probabilities are added together.