Vig And No-Vig Calculator

The vig is the commission built into the prices themselves. It never appears as a line item, it is charged whether you win or lose, and it is the reason a bettor who picks winners half the time goes broke.

Enter both sides of a market to see the margin, the hold, and what each side would be priced at if the book took no cut at all.

Overround, Hold And Why They Differ

Two numbers describe the same margin from different angles, and they are routinely confused.

Overround is how much the implied probabilities exceed 100%. A -110 pair implies 52.38% twice, so the total is 104.76% and the overround is 4.76%.

Hold is the share of money staked the book keeps if action is balanced. It is 1 − (1 ÷ total), which for the same market is 1 − (1 ÷ 1.0476) = 4.55%.

Hold is the honest figure, because it is expressed against the money rather than against the probabilities. On a standard -110 spread the book keeps about $4.55 of every $100 wagered across both sides. That is the toll you pay for the privilege of having an opinion, and it is charged on turnover, not on profit.

Stripping The Vig Out

De-vigging assumes the margin is spread across the sides in proportion to their implied probabilities, then divides it back out.

Worked example. A book posts -140 on one side and +120 on the other. Raw implied probabilities are 58.33% and 45.45%, totalling 103.79%.

Fair probability for the favourite = 58.33 ÷ 103.79 = 56.20%. For the underdog = 45.45 ÷ 103.79 = 43.80%. Those now sum to exactly 100%.

Fair prices are 1 ÷ 0.5620 = 1.7794, or about -128, and 1 ÷ 0.4380 = 2.2831, or about +128. The market's real opinion is a 56-44 game; the posted -140 is that opinion plus commission.

This is the number your own estimate has to beat. Comparing a 57% projection to the posted 58.33% says "no bet"; comparing it to the fair 56.20% says there is a small edge. Reading the vig-inclusive figure as the market's opinion is the most common way bettors overestimate how often they disagree with the market.

How Much Vig Costs Across A Season

Hold is small per bet and enormous per season, because it applies to every bet rather than to your net result.

Take 500 bets of $100 at -110. That is $50,000 of turnover, and a 4.55% hold on balanced action is $2,275. To finish level you have to out-predict the market by enough to cover it — roughly 2.4 percentage points of win rate, every bet, all season.

Shopping for -105 instead of -110 cuts the two-way hold from 4.55% to about 2.44%. On the same turnover that is roughly $1,000 back, which for most bettors is larger than any edge their handicapping produces.

Props, alternate lines and same-game parlays are typically held at three to five times these rates, which is the real reason they are pushed so hard.

Three-Way Markets And Where De-Vigging Breaks Down

Soccer, and any market with a draw, needs all three prices. Decimal 2.10, 3.40 and 3.60 imply 47.62%, 29.41% and 27.78%, totalling 104.81% for a hold of 4.59%. The fair probabilities are 45.44%, 28.06% and 26.50%.

The proportional method used here is the standard one, and it is an approximation. It assumes the margin is loaded evenly across sides, and books do not always oblige: on longshots the margin is often loaded onto the outsider, which makes the proportional fair price on a big underdog slightly too generous. That bias grows with the price, so treat de-vigged numbers on a +2000 futures market as indicative rather than exact.

For markets with many outcomes — a 30-team futures book totalling 120% — de-vigging one runner in isolation is not meaningful at all. Use the whole board, and read futures betting for why those markets carry so much margin in the first place.

Frequently Asked Questions