No-Vig Fair Odds Calculator
Enter the prices for a market and this removes the margin, returning the implied probabilities, the booksum, the hold, and the fair odds with the vig taken out. Nothing is sent anywhere — the arithmetic runs entirely in your browser.
- Booksum
- 104.76%
- Margin
- 4.76%
- Hold
- 4.55%
| Outcome | Implied | Fair | Fair odds |
|---|---|---|---|
| Team A | 52.38% | 50.00% | +100 |
| Team B | 52.38% | 50.00% | +100 |
Divides every implied probability by the booksum. The standard method — simple, and it keeps each outcome’s share of the market proportional.
Fair probability by method
| Outcome | Multiplicative | Additive | Power | Shin |
|---|---|---|---|---|
| Team A | 50.00% | 50.00% | 50.00% | 50.00% |
| Team B | 50.00% | 50.00% | 50.00% | 50.00% |
Informational and educational only. 18+. This tool performs arithmetic on figures you enter; it does not recommend any outcome and makes no prediction.
The same market, margin removed
Four common two-way shapes, de-vigged multiplicatively. Every figure below is computed by the same code the calculator runs, so it cannot drift from it.
| Market | Prices | Margin | Fair probabilities | Fair odds |
|---|---|---|---|---|
| Even map, standard price | -110 / -110 | 4.76% | 50.0% / 50.0% | +100 / +100 |
| Slight favourite | -140 / +120 | 3.79% | 56.2% / 43.8% | -128 / +128 |
| Clear favourite | -250 / +200 | 4.76% | 68.2% / 31.8% | -214 / +214 |
| Heavy favourite | -600 / +425 | 4.76% | 81.8% / 18.2% | -450 / +450 |
The method, in four steps. Convert each price to a probability (decimal odds become 1 ÷ price; −110 becomes 110 ÷ 210 = 52.38%). Add them up — on a fair market they would total exactly 100%, but in practice they total more, and that excess is the margin. Remove it: multiplicative divides each probability by the booksum, so 52.38% ÷ 1.0476 = 50%. Convert back — a fair 50% is decimal 2.00, or +100.
The long version, with charts, is the vig explained: how de-vigging finds fair odds, and the terms are defined one by one in vig, de-vigging, implied probability and market line. This is the same arithmetic behind the single CS2 market line we publish — see the methodology.
No-vig and fair-odds questions
- What does a no-vig calculator do?
- It removes the margin baked into a set of odds, so the implied probabilities add up to exactly 100% instead of more. What is left is the "fair" or "no-vig" probability of each outcome, and the fair price that corresponds to it.
- Which de-vig method should I use?
- Multiplicative is the standard default: it divides each probability by the booksum, keeping every outcome’s share proportional. Additive, power and Shin all take proportionally more off longshots, which some research argues better reflects how margin is really applied. This page computes all four at once so you can see how much the choice actually moves the answer — on a tight market, very little; on a longshot, a lot.
- What is the difference between margin and hold?
- Margin is the booksum minus 100%. Hold is that margin expressed as a share of the booksum — the theoretical proportion of staked money retained. For a −110/−110 market the margin is about 4.76% and the hold about 4.55%.
- Why does it sometimes refuse to give an answer?
- Because the honest answer is that there isn’t one. If your prices already sum to 100% or less there is no margin to remove, and the additive method can drive a big longshot below zero. In both cases the tool says so rather than printing a number that looks fine and isn’t.
- Does esportsodds.gg publish odds like this?
- We publish one derived market line for CS2, combined from multiple bookmakers and exchanges and de-vigged with the same arithmetic this page performs. We never publish an individual bookmaker’s price and never name a contributing source. The methodology is documented in full.
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