No-Vig Calculator
Enter the prices of every outcome in a market to strip out the vig and see the fair odds, the fair probability of each side and how much the sportsbook keeps. American odds by default, decimal and fractional too, for two-way markets (spreads, totals, moneylines) and three-way markets (soccer 1X2). Then check whether a price at another sportsbook beats the fair line.
In one line: -150 implies 60.00% and +130 implies 43.48%. Together that is 103.48%, so the vig is 3.48%. Scaled back to 100%, the fair probabilities are 57.98% and 42.02% and the no-vig line is -138 / +138. A sportsbook offering +145 on the underdog is then a bet worth +2.94% of the stake on that estimate. Full method below.
60.00% implied
43.48% implied
Fair Odds by Outcome
| Outcome | Price | Implied | Fair probability | No-vig odds |
|---|---|---|---|---|
| Side A (e.g. favourite) | -150 | 60.00% | 57.98% | -1381.725 decimal |
| Side B (e.g. underdog) | +130 | 43.48% | 42.02% | +1382.380 decimal |
Fair probabilities add up to exactly 100%. The gap between the implied and the fair column is the share of the vig loaded on each outcome under the multiplicative method.
Check a Price Against the Fair Line
Found a different price on the same outcome at another sportsbook? Enter it to see its expected value against the no-vig probability above.
The Vig in This Market
How to Remove the Vig: Worked Example
Take a moneyline of -150 on the favourite and +130 on the underdog.
- Implied probability of each side. Negative odds: odds / (odds + 100), so 150 / 250 = 60.00%. Positive odds: 100 / (odds + 100), so 100 / 230 = 43.48%.
- Add them up. 60.00% + 43.48% = 103.48%. A fair market would add up to exactly 100%, so the vig (overround) is 3.48%. On a book balanced by money, the sportsbook keeps 1 − 1 / 1.0348 = 3.36% of everything staked: that is the hold.
- Scale back to 100%. With the multiplicative method each probability is divided by 1.0348: 60.00% becomes 57.98% and 43.48% becomes 42.02%.
- Turn the fair probabilities into odds. 1 / 0.5798 = 1.725 in decimal, which is -138 in American odds; 1 / 0.4202 = 2.380, which is +138. The no-vig line is -138 / +138.
- Compare with other prices. If another sportsbook offers +145 (2.45 decimal) on the underdog, the expected value is 0.4202 × 2.45 − 1 = +2.94% of the stake. If it offers -135 on the favourite, the edge is +0.93%.
On the standard -110 / -110 spread or total the same steps give 52.38% + 52.38% = 104.76%: a 4.76% vig, a 4.55% hold and a no-vig line of +100 on both sides. That 4.55% is the figure usually quoted as the house edge on a standard spread bet, and it is why a bettor laying -110 needs to win 52.38% of the time just to break even: see the break-even odds calculator.
Multiplicative, Additive or Power: Why the Fair Line Changes
There is no single correct way to split the vig between the outcomes. The three methods in the calculator agree on an even market and drift apart as the favourite gets shorter:
| Market | Vig | Multiplicative | Additive | Power |
|---|---|---|---|---|
| -110 / -110 | 4.76% | +100 / +100 | +100 / +100 | +100 / +100 |
| -150 / +130 | 3.48% | -138 / +138 | -140 / +140 | -140 / +140 |
| -300 / +240 | 4.41% | -255 / +255 | -268 / +268 | -275 / +275 |
Multiplicative (also called proportional or normalisation) divides every implied probability by the total. It assumes the sportsbook loads the vig in proportion to each price.
Additive takes the same number of percentage points off every outcome: on -300 / +240 that is 2.21 points each. On a heavy longshot it can push the probability below zero, which is why the calculator refuses it there.
Power finds the exponent k for which the implied probabilities raised to k add up to 100%. Longshots lose proportionally more, in line with the favourite-longshot bias: bettors overpay for longshots, so sportsbooks can load more margin on them. On -300 / +240 the power method makes the favourite -275 where the multiplicative method says -255.
For a decision that turns on a small edge, run all three: if the bet is only positive under one method, the edge is inside the uncertainty of the method itself.
Implied Probability of Common American Odds
Implied probability is the win rate a price needs to break even, vig included. These are the reference values; any other price can be typed into the calculator or the odds converter.
| American | Decimal | Implied probability |
|---|---|---|
| -300 | 1.33 | 75.00% |
| -200 | 1.50 | 66.67% |
| -150 | 1.67 | 60.00% |
| -110 | 1.91 | 52.38% |
| +100 | 2.00 | 50.00% |
| +130 | 2.30 | 43.48% |
| +200 | 3.00 | 33.33% |
| +400 | 5.00 | 20.00% |
One side of a market on its own tells you the price, not the probability: -110 implies 52.38%, but the other side at -110 implies the same, and both cannot be true. Only by devigging the whole market do you get a fair estimate, here 50%.
Where the No-Vig Line Is Useful
Line shopping. The fair line from a low-vig market is a yardstick for every other price on the same outcome. A price longer than the fair odds is worth a closer look; a shorter one is paying the vig twice.
Parlays and boosts. The vig on each leg multiplies through a parlay. Devig each leg, multiply the fair probabilities, and compare the result with the boosted parlay price in the parlay calculator to see whether a boost is worth taking.
Staking. A fair probability is the input the Kelly criterion calculator needs. The fair line is an estimate built on someone else's market, not a forecast of your own, so most bettors who use it stake a fraction of Kelly.
Prices that add up to less than 100% across different sportsbooks are not a market to devig but an arbitrage: use the arbitrage calculator instead. For decimal-odds markets with more than three outcomes, the bookmaker margin calculator shows the overround the UK way.
Frequently Asked Questions
What does no-vig mean in sports betting?
No-vig (or vig-free) odds are the prices a market would show if the sportsbook took no commission. Every price is turned into an implied probability; on a real market those probabilities add up to more than 100%, and the excess is the vig. Scaling them back to exactly 100% gives the fair probability of each outcome and the fair odds that go with it. A -110 / -110 market adds up to 104.76%, so the no-vig line is +100 on both sides.
How do you calculate implied probability from American odds?
For negative odds, divide the odds by the odds plus 100: -150 is 150 / 250 = 60%. For positive odds, divide 100 by the odds plus 100: +130 is 100 / 230 = 43.48%. Add the implied probabilities of every outcome and subtract 100% to get the vig in the market: here 60% + 43.48% = 103.48%, a 3.48% overround.
Which devig method should I use?
On an even market every method gives the same answer. On a market with a clear favourite they differ: the multiplicative method takes the vig off in proportion to each price, while the additive and power methods take more of it off the longshot, which matches the favourite-longshot bias seen in betting data. Multiplicative is the common default; if the fair prices matter to a decision, check that all three point the same way.
How do I use a no-vig line to find value?
Devig a market you trust, usually the sharpest sportsbook with the lowest vig, then compare its fair odds with the price another sportsbook offers on the same outcome. If the offered price is longer than the fair price, the bet has positive expected value on that estimate: the calculator shows the edge as a percentage of the stake. A fair line is an estimate, not a guarantee, and a small edge still loses often.
A positive expected value is a long-run average, not a promise: a bet with a 3% edge still loses most of the time at plus-money odds. Bet only where sports betting is legal for you and you meet the minimum age (18+, and 21+ in most US states). Set a budget and stick to it. Verdecto does not take bets. If gambling stops being fun, see our responsible gambling resources; in the US you can call 1-800-GAMBLER.