No Vig Calculator

Use this no vig calculator to strip the sportsbook’s margin out of a set of odds. Enter the price on every outcome of a market and it gives the fair odds and the true probability behind each one. It works for two-way lines, three-way markets and futures boards, and it shows three ways of removing the vig side by side, because they don’t always agree.

About the no vig calculator

Most no-vig tools take two prices, apply one formula and hand back one answer. That’s fine on a coin-flip line. It hides something on a lopsided one: the answer depends on how you assume the book spread its margin, and reasonable assumptions give different fair odds.

• Two outcomes or up to eight. Spreads and totals, soccer three-ways, and futures.
• Three methods at once. Multiplicative, additive and power, in one table.
• Hold and overround, both. They’re different numbers, and sites mix them up.
• A bet check. Enter a price from another book and see the expected value, by each method.
• American or decimal odds. Switch and the numbers you’ve typed convert.
• The working. Every step, so you can check it by hand.

It runs in your browser. Nothing you enter is sent anywhere or saved. It’s arithmetic on the prices you give it, not a prediction and not betting advice.

How to use the no vig calculator

1. Pick the odds format. American or decimal.
2. Enter the odds for every outcome of one market at one sportsbook. Add a row for each extra outcome.
3. Read the fair odds in the headline, and the hold beside them.
4. Compare the methods in the table.
5. Check a bet by entering the price another book offers on one of the outcomes.

What the vig is

A sportsbook doesn’t offer fair odds. It shades every price a little in its own favor. That shading is the vig, short for vigorish. It’s also called the juice, the margin or the take.

You can see it by turning odds into implied probabilities. A price implies a chance of winning: the chance at which a bet at that price would break even. Add up the implied chances for every outcome of a fair market and you get 100%. Do it with a sportsbook’s prices and you get more.

The standard example is a point spread at -110 on each side. Each price implies 52.38%. Together that’s 104.76%. Two things can’t both have a 52.38% chance when only one can happen. The extra 4.76% is the vig.

The no vig calculator formula

Step 1: implied probability.

negative American odds:  implied = odds / (odds + 100), ignoring the minus sign
positive American odds:  implied = 100 / (odds + 100)
decimal odds:            implied = 1 / odds

So -110 is 110 / 210 = 52.38%, and +150 is 100 / 250 = 40%.

Step 2: add them up. The total is more than 100%.

Step 3: remove the extra. The usual way is to divide each implied probability by the total:

fair probability = implied probability / total of all implied probabilities

Step 4: turn the fair probability back into odds.

decimal odds = 1 / fair probability

A worked example

A moneyline is -150 on the favorite and +130 on the underdog.

1. Implied: 150 / 250 = 60.00%, and 100 / 230 = 43.48%.
2. Total: 103.48%.
3. Fair: 60.00 / 103.48 = 57.98%, and 43.48 / 103.48 = 42.02%.
4. Fair odds: -138 and +138.

Fair odds on a two-way market always mirror each other. If one side is -138, the other is +138.

Hold and overround are not the same number

Betting sites use “vig”, “hold” and “juice” loosely. There are two precise measures, and they differ.

Check the hold by hand. Two people bet $110 each on opposite sides at -110. The book takes in $220. It pays the winner $210: the $110 stake back plus $100. It keeps $10. And $10 / $220 = 4.55%.

At least one popular calculator reports 4.8% for this line and calls it the hold. The no vig calculator shows both figures and labels them.

Common lines, with the vig removed

A reduced-juice book at -105 / -105 holds about half what a standard book does on the same market. Over hundreds of bets, that difference adds up.

Three ways to remove the vig

This is where the no vig calculator differs from most. Dividing by the total is one assumption about where the book put its margin. There are others. These three are documented for “implied”, an open-source R package built for this job.

On an even line all three give the same answer. As the favorite gets heavier, they pull apart, and the underdog’s fair price is where it shows.

Look at the last row. The book offers +650. Is the fair price +682, +792 or +878? It depends on the method, and the multiplicative one is always the kindest to the longshot.

Which is right? Nobody can say for certain. The package’s own documentation says the multiplicative method “tend to be the least accurate of the methods in this package”, and that’s the method nearly every free calculator uses. The practical lesson is to treat the three figures as a range.

When the additive method breaks

The additive method takes an equal slice off every outcome. On a big board with rank outsiders, that slice can be larger than an outsider’s whole implied probability. The result is a chance below zero, which is nonsense. The same documentation warns that the method “can produce negative probabilities”. When that happens, the no vig calculator says so and points you to the other two.

Methods we don’t include

That package also covers Shin’s method, the odds-ratio method and several more. We left them out to keep the tool readable. On a two-outcome market, the documentation notes, the additive method and Shin’s method give the same result.

Three-way markets and futures

The no vig calculator isn’t limited to two sides. The same steps work for any number of outcomes, as long as you enter all of them.

A soccer match priced at +150 home, +230 draw and +190 away:

• Implied: 40.00%, 30.30% and 34.48%. Total 104.79%.
• Hold: 4.57%.
• Fair odds, multiplicative: +162, +246 and +204.

A published three-way example. The package documentation works through decimal odds of 4.20, 3.70 and 1.95. Our figures match theirs: 23.32%, 26.47% and 50.22% by the multiplicative method, and 23.10%, 26.32% and 50.58% by the additive method. The engine’s tests check this to seven decimal places.

A futures board only works if it’s complete. If a book lists 30 teams to win a title and you enter the top six, the total will come in under the truth and every fair price will be wrong. The calculator takes up to eight outcomes, so it suits small fields, not a 30-team board.

Checking a bet: expected value

The last section of the no vig calculator checks a bet. Fair odds are a yardstick. If another book offers a better price than the fair one, the bet has positive expected value by that yardstick.

expected value = fair probability x decimal odds - 1

Example. One book has -150 / +130. The underdog’s fair chance, multiplicative, is 42.02%, which is +138. A second book offers the underdog at +145, which is 2.45 in decimal.

• Expected value: 0.4202 x 2.45 – 1 = 2.94%.
• On a $100 stake, that’s $2.94 a bet on average.

Now run the same bet through the other methods. Additive gives 2.26%. Power gives 1.92%. All positive, so the three agree on the direction.

That isn’t always so. Take -300 / +240 and an underdog price of +260 elsewhere. Multiplicative says +1.41%. Additive says -2.06%. Power says -3.91%. The no vig calculator flags a bet like this, because an edge that depends on which formula you picked isn’t an edge you can count on.

Two more cautions. Expected value is an average over many bets. Any single bet wins or loses in full. And the whole exercise assumes the first book’s line is a good estimate of the truth. If that book is wrong, the fair odds are wrong too.

Which book’s line to strip

Bettors who use this approach usually take their fair odds from the book they consider sharpest on that market, meaning the one whose prices tend to be closest to the eventual result, and then look for softer books offering more. Which books are sharp is a matter of opinion and changes by sport. We don’t rank them.

Whatever you choose, take all the prices from one book at one moment. Mixing one side from each of two books isn’t a market. It’s two half-markets, and the total can come to less than 100%. The calculator warns you when it does.

Reading your result

• No-vig odds. The fair price of each outcome by the method you chose.
• Hold. The book’s share of money staked on a balanced market.
• Overround. How far the implied probabilities overshoot 100%.
• Expected value. Appears when you enter a bet. Positive means the price beats the fair price.
• The table. Book odds, implied probability, and the fair probability and odds by each method.

Common mistakes

• Entering part of a market. Every outcome has to be there.
• Mixing books. One book, one moment.
• Calling the overround the hold. 4.76% and 4.55% on a standard line.
• Trusting one method on a heavy favorite. The fair price of a big underdog can move by a hundred points or more between methods.
• Treating fair odds as the truth. They’re one book’s opinion with the margin removed.
• Reading a small edge as a sure thing. A 2% edge loses often.

What the no vig calculator can’t tell you

• Who will win. It reads prices. It doesn’t predict games.
• Whether a book is sharp.
• Where the book really put its margin. Only the book knows.
• How much to stake. There’s no staking advice here.
• Whether betting is legal where you are. Rules vary by state and country.

Betting carries a real risk of losing money. Most bettors lose over time, because the vig is working against them on every bet. If gambling is causing you harm, in the US you can call 1-800-GAMBLER.

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If you like chance problems, the OSRS dry calculator works out the odds of going without a rare drop. For money you’d rather grow than risk, the DRIP calculator shows what reinvested dividends add up to, and the CoastFIRE calculator shows how much you need invested to stop saving for retirement. Everything else is on the all tools page.

Method and sources

• Jonas Lindstrom, “implied: Convert Between Bookmaker Odds and Probabilities”, R package vignette on CRAN, read October 9, 2026: the multiplicative, additive and power formulas, the worked three-way example, and the two quoted remarks.
• The hold formula and the -110 / -110 check are arithmetic, shown above.