No-Vig Calculator

Strip the bookmaker margin out of a market to reveal the fair odds and the true implied probability of each outcome.

A no-vig calculator removes the bookmaker’s built-in margin from a market and shows you the fair odds and true implied probabilities of every outcome, so you can benchmark any other price against them.

What Is the No-Vig Price?

The no-vig price — also called the fair odds — is what the odds would be if the bookmaker had no margin. It is the pure market-implied probability converted back into decimal format. Where the margin calculator tells you how much the market is marked up, the no-vig calculator shows you what the prices would be if they were not marked up at all.

To understand this, imagine a coin flip: fair odds on both sides should reflect 50.0% probability each. A bookmaker offering 1.90 on both sides builds in margin. When you strip the vig from a 1.90 / 1.90 market, you recover the fair odds of 2.00 and the true probabilities of 50.0% on each side.

Fair odds are your value benchmark. Professional bettors use no-vig odds as their primary tool when shopping across bookmakers. Odds longer than fair deserve backing; shorter odds should be avoided. The benchmark quantifies exactly how much better or worse each offer is, in real terms rather than guesswork.

Understanding fair prices protects you from the illusion of choice. Bookmakers priced at 1.95 and 1.85 look different but both compress to 2.00 fair odds when the margin is stripped. No-vig odds show true market opinion, independent of the bookmaker’s margin.

Fair odds are most powerful when applied systematically. Over hundreds of bets, small advantages compound into profit. Professionals use the no-vig calculator as the foundation of value hunting: it answers whether a price is longer than the market thinks.

How Fair Odds Are Calculated

Fair odds are calculated by removing the margin proportionally across every outcome. First, convert each bookmaker price to its implied probability using one divided by the decimal odds. Second, add those probabilities to get the total. This total always exceeds fair value; the excess is the bookmaker’s margin, called the vig or the overround. Third, divide each individual probability by that total to get the fair probability. Fourth, convert the fair probability back to odds by taking one divided by the fair probability.

This four-step process isolates market truth from the bookmaker’s markup. Implied probabilities always sum above fair value; that excess is the vig. Normalising each probability against the total removes the markup systematically while keeping the proportional relationship between outcomes intact.

The calculation works the same for two-way or multi-outcome markets like 1X2 football. The principle: add implied probabilities, divide each by the total, convert back to odds.

Proportional removal assumes the margin is spread evenly. In practice, bookmakers often place more margin on longshots than favourites, so calculated fair odds on outsiders may be slightly shorter than true fair value. Despite this, the method remains the best simple benchmark for comparing prices across bookmakers.

The key insight is that fair odds are always longer than priced odds. This makes intuitive sense: the priced odds include the bookmaker’s edge, so removing it gives back longer prices. A two-way market priced at 1.90 on both sides has a fair price of 2.00 on both sides. A 1X2 priced at 2.20 home, 3.40 draw, 3.30 away has fair odds of 2.31, 3.58 and 3.47 respectively — every single one longer than the price the bookmaker quoted. This directional shift is consistent: never expect a fair odd to be shorter than the priced odd.

What the Calculator Shows You

Enter the bookmaker’s decimal prices for every outcome and the calculator converts each to an implied probability, calculates the total, divides proportionally to get fair probabilities, and converts back to odds. Fair odds are the prices you would get with the margin removed — this is the benchmark you compare other bookmakers against. Fair probability is the true chance implied by the market, expressed as a percentage.

The calculator also shows you the total implied probability and therefore the size of the margin. This three-piece output tells you everything: what the fair price is, what the true implied probabilities are, and how much the bookmaker is taking out. On a heavily marked-up market with a large margin, the gap between priced and fair odds is wide. On a tight market, it is narrow. The wider the gap, the more important it is to shop for better prices.

Each output serves a distinct purpose. The fair odds are your decision-making tool when shopping for the best price: if a bookmaker quotes longer than the fair odds, take it; if they quote shorter, walk away. The fair probabilities show what the market truly believes once the margin is removed. The total implied probability is your margin gauge — at 105.26%, the bookmaker is taking 5.26%. Understanding this gap matters because small differences in margin transform losses into profits across hundreds of bets.

Worked Example

Take a two-way Over/Under market priced at 1.90 on both sides. The total implied probability is 105.26%. When you remove the vig and allocate the fair probabilities, each outcome has a fair probability of 50.0%. Converting back to odds gives 2.00 on each side.

The no-vig price on a 1.90 / 1.90 market is therefore 2.00 / 2.00. This illustrates the principle clearly: a bookmaker offering 1.90 / 1.90 is shorter than the fair price of 2.00 / 2.00. The fair odds show you exactly how much shorter, and give you a benchmark to compare against other bookmakers pricing the same market.

The 5.26% total implied probability above the break-even point is the bookmaker’s margin on this market. When you strip it away, the fair price reverts to 2.00, which is a true coin flip. This calculation makes it concrete and measurable when comparing across bookmakers.

Stripping the Vig From a Three-Way 1X2 Priced 2.20 / 3.40 / 3.30

The table below shows a 1X2 market with both the bookmaker’s priced odds and the fair odds once the margin is removed.

Notice that every fair odd is longer than the priced odd. Home goes from 2.20 to 2.31, Draw from 3.40 to 3.58, Away from 3.30 to 3.47. The shift is proportional: outcomes that seemed less likely get slightly more probability allocated when the margin is removed, and outcomes that seemed likely get slightly less.

Two-Way Market: Priced Odds Against Fair Odds

Different priced levels on two-way markets all compress to the same fair odds when the margin is removed. The table below shows how 1.95, 1.90 and 1.85 priced on both sides of a two-way market all become 2.00 fair odds.

This shows why no-vig odds are so powerful as a benchmark. Multiple bookmakers might price the same two-way market at different levels — 1.95, 1.90, 1.85 — each carrying a different margin. But they all have the same fair odds of 2.00 underneath, which is the true fair price.

Proportional Vig Removal and Skewed Margins

The fair odds calculated by proportional vig removal assume the bookmaker’s margin is spread evenly across every outcome. In reality, bookmakers often place more of the margin onto longshots than onto favourites. The true fair price on an outsider can be slightly longer than this calculator suggests, while the fair price on a short favourite might be slightly shorter.

This skew reflects market reality. Bettors love longshots and accept shorter value, so bookmakers place more margin there. Proportional vig removal does not account for this bias, so treat calculated fair odds on outsiders as a conservative estimate.

The result is the best simple benchmark available for comparing prices across bookmakers. It is a close estimate rather than exact truth, but far more reliable than any individual bookmaker’s price.

When Fair Odds Matter

Fair odds matter most when comparing a bookmaker’s prices against a benchmark. If shopping for the best price on a selection, you calculate the fair odds once and then check every bookmaker against that standard. Over hundreds of bets, this discipline compounds into real profit — small edges accumulate when applied consistently.

Fair odds also matter when assessing whether a price deserves backing. Most bettors rely on gut feel; professionals benchmark against fair odds first. This is critical when evaluating tight markets — a price at or below fair odds is typically not worth backing, since you are paying the bookmaker’s margin to play a break-even or negative-value bet.

When comparing prices across multiple bookmakers on the same event, fair odds are your objective baseline. Rather than trying to compare many different quotes subjectively, you calculate fair odds once and then systematically check each bookmaker’s offer. This eliminates emotion and makes value concrete.

Common Mistakes

Many bettors compare one bookmaker’s priced odds against another’s instead of against fair odds, missing value. Without knowing fair odds, you cannot tell whether a price offers genuine value or is worse than the true market. Fair odds reveal this; comparing prices head-to-head does not.

Others leave an outcome out of the market when calculating fair odds, distorting every fair price downstream. A 1X2 market must include all three outcomes. Missing any distorts the calculation and breaks the entire result.

Some expect fair odds to be shorter than priced odds, forgetting they are always longer — the margin shortens every price. Once you remove the bookmaker’s edge, prices must extend.

Finally, bettors treat fair odds as exact truth, forgetting that skewed margins make calculated outsider odds conservative estimates. Use the result as a strong benchmark, not gospel.

No-Vig vs Margin and Hold

These three calculators all strip the margin out or quantify it, but in different ways. Margin tells you the percentage by which the market is marked up. Hold tells you the percentage of turnover the bookmaker expects to keep. No-vig tells you what the odds would be with the margin removed.