No-Vig Calculator

Worked example: removing the vig from -110/-110

Start with the most common two-way price in American sports betting: both sides priced at -110. Converting -110 to implied probability divides the absolute value of the odds by itself plus 100: 110 divided by 210 equals 0.5238, or 52.38%. Because both sides carry the same price, each side works out to the identical 52.38% implied probability.

Add the two implied probabilities together and the total comes to 104.76%, not 100%. That extra 4.76% is the sportsbook's vig — the built-in margin that guarantees the book a profit if it takes roughly balanced action on both sides, regardless of which side ultimately wins. (A book sitting on lopsided one-sided action can still lose on a game despite the vig; the margin protects the book's average across bettors, not any single outcome.) To remove the vig, divide each side's implied probability by the market total: 52.38% divided by 104.76% equals exactly 50.00% for each side. A -110/-110 market's fair, no-vig price is therefore even money on both sides — that's the market's own fair-price estimate of a coin flip, not proof that the underlying game itself is one; the book's assessment baked into that price can still be wrong.

Now try an uneven market: -150 on the favorite and +130 on the underdog. -150 converts to 150 divided by 250, or 60.00% implied probability. +130 converts to 100 divided by 230, or 43.48%. The two add up to 103.48%, so the vig here is only 3.48% — thinner than the -110/-110 market — moneylines are often posted with less margin than standard-juice spreads, but the vig depends on the exact pair of prices, not on distance from even money. Dividing each side by 103.48% gives no-vig probabilities of 57.98% for the favorite and 42.02% for the underdog. Converting those back into American odds produces a fair line of roughly -138 on the favorite and +138 on the underdog, a tighter and genuinely symmetric price compared with what the book actually offers.

When to use multiplicative devig

This calculator uses the multiplicative method: it converts each side to implied probability, adds them up, and divides each one by that total so the results sum to exactly 100%. It is the simplest devig approach, and a reasonable default whenever the two prices sit reasonably close to even money, because it spreads the vig proportionally across both sides.

Multiplicative devig gets less predictable the more lopsided a market becomes, because it removes the same percentage share of margin from both sides no matter how far apart their raw probabilities already sit. Take a heavy favorite like -900/+550: the raw implied probabilities are 90.00% and 15.38% (a 105.38% total, or a 5.38% vig). Multiplicative devig divides each side by that total for an 85.40%/14.60% fair split. Additive devig instead subtracts the vig as an equal number of percentage points from each side — 2.69 points off both — for an 87.31%/12.69% split, nearly two full points higher on the favorite than multiplicative gives it. The power method raises each implied probability to an exponent chosen so the results sum to 100%, and Shin's method models the market as if a fraction of bettors hold inside information; both can land closer to either of the other two depending on how lopsided the market is.

Treat the multiplicative result here as a reliable baseline for two-way markets close to a coin flip, and as a rougher estimate the further a market drifts toward a heavy favorite or a big underdog. Comparing several devig methods side by side, covered in the devig methods guide, shows how much model risk a single method can hide, and is the more defensible approach whenever a market carries a wide spread between its two prices.

Reading the vig percentage: cost, not just margin

The 4.76% vig figure on -110/-110 isn't quite the same thing as the sportsbook's expected cut of every dollar wagered. That second figure — the hold — is the vig expressed as a share of the total market rather than of the fair price: 0.047619 divided by 1.047619 works out to a 4.55% hold. On the -150/+130 market, the 3.4783% vig converts to a 3.36% hold by the same division. The two numbers move together, but they answer slightly different questions: vig tells you how far the quoted prices sit from a fair line, and hold estimates the bookmaker's average take across everyone betting that market.

A thinner vig is not automatically a better bet for you. -110/-110 carries a thicker 4.76% vig than -150/+130's 3.48%, but thickness alone says nothing about whether either side is worth taking; that still depends on whether your own probability estimate clears the price you'd actually be paying. On -110/-110, that bar is the raw 52.38% implied probability of the -110 price itself, not the 50.00% no-vig figure — a 51% estimate beats the no-vig number but is still a losing bet at -110 (roughly -$2.64 expected value per $100 wagered) because it falls short of the 52.38% breakeven. Use the vig percentage to compare how expensive two otherwise-similar markets are to bet into, and use each side's own raw implied probability, not the no-vig figure, as the break-even bar for whether that specific price is worth taking; the no-vig probability is better used as a fair-market benchmark for comparing books or tracking closing line value.

Vig reference: common two-way price pairs

Running the same divide-and-normalize arithmetic across other common two-way price pairs shows how quickly the vig shrinks as a market moves away from -110/-110: -105/-105 clears at a 2.44% vig, -120/+100 clears at 4.55%, -130/+110 clears at 4.14%, -200/+170 clears at 3.70%, and -300/+250 clears at 3.57%. A +100/+100 line — true, unpriced even money on both sides — is the one common two-way quote with a 0.00% vig, which is why sportsbooks essentially never post it on a genuine coin-flip market.

None of those vig figures tell you which side to bet; they only describe how much room the book has built into that particular pair of prices before either side becomes a fair bet. A 2.44% vig on -105/-105 is cheaper to bet into than a 4.76% vig on -110/-110, all else equal, but a bettor with no edge loses to either market over time — the thinner vig just slows down how fast that expected loss accumulates.

A slightly less obvious pair worth checking by hand: -105/-115. Averaging the two prices gives -110, the same average as a plain -110/-110 line, but the vig works out to 4.71% instead of 4.76% — close, not identical, because implied probability is a nonlinear function of American odds. Two other uneven pairs illustrate the same point: -175/+155 clears at a 2.85% vig and -225/+185 clears at a 4.32% vig, despite both favorites sitting well clear of even money. There is no shortcut that estimates vig from the two raw numbers alone; running the actual implied-probability arithmetic on both sides is the only reliable way to know a market's true margin.

No-vig probability as a closing-line benchmark

The same no-vig probability this calculator produces is also the standard yardstick for measuring closing line value (CLV). Suppose you bet a favorite at -120 (54.55% raw implied probability) and the market later settles at -140/+120 before kickoff. Devigging that closing line the same way as any two-way market gives a 56.20% no-vig probability for the favorite — noticeably higher than the 54.55% you paid for. The market moved toward your side after you bet it, which is a meaningful signal about the quality of your original read, independent of whether the bet itself ultimately wins or loses.

Tracking that gap over many bets — your entry price's implied probability against the closing line's no-vig probability — is far more informative than tracking win rate alone, because win rate is noisy over any realistic sample while consistently beating the closing no-vig number tends to show up quickly. Run this calculator on the closing line for every bet you place, log the no-vig probability it produces, and compare it against the number you actually got; a bettor who reliably buys below the eventual no-vig line is finding real value even during a losing stretch.

What the vig costs across a full night of betting

Zoom out from a single bet to a full night of action and the vig turns into a concrete dollar figure. If a sportsbook takes $100,000 in total wagers split evenly across both sides of a -110/-110 market, its expected hold — the 4.55% figure from the earlier hold-versus-vig comparison — works out to roughly $4,545 before accounting for any skew in which side actually wins. No individual bettor pays exactly 4.55% on their own ticket; the figure describes the book's expected take across the whole handle, which is precisely why a bettor with a genuine edge on one side can still show a profit even as the book profits on average across everyone else.

The math holds at extreme prices too

'Juice' is used interchangeably with 'vig' throughout the industry, and the underlying arithmetic doesn't change no matter which word a book or a bettor reaches for. Even a lopsided price most bettors will never see quoted this wide, -10000/+3000, resolves the same way: 99.01% and 3.23% raw implied probabilities, a 2.24% vig, and no-vig probabilities of 96.84% and 3.16%. Whether a market is a coin flip or a near-lock, dividing each side's implied probability by the market total is the entire method — there is no separate formula for extreme prices.

More price pairs at a glance

A longer quick-reference list, for spot-checking this calculator against a spreadsheet: -140/+115 clears at a 4.84% vig, -160/+140 at 3.21%, -190/+160 at 3.98%, -240/+200 at 3.92%, -260/+220 at 3.47%, and -280/+235 at 3.53%. None of these follow a simple pattern as the favorite gets bigger — the vig depends on the exact relationship between both quoted prices, not on how far either one sits from even money, which is the whole reason a calculator is more reliable here than an eyeballed estimate.

For anyone who wants bit-for-bit reproducibility rather than a rounded percentage, -140/+120 reduces to exact fractions: 7/12 and 5/11 raw implied probability. Their sum is 137/132, so the exact no-vig values are 77/137 (56.2044%) and 60/137 (43.7956%) — the same figures this calculator rounds to 56.20% and 43.80% on screen.