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What Is the Vig? How a -110 Line Prices In the Sportsbook's Margin
A -110 price on a spread bet is not "even money with a discount." It is the sportsbook's built-in margin, the vig or juice, priced into almost every line. Knowing how it works tells you what a bet actually costs.
What the Vig Actually Is
The vig is the fee a book charges for taking a bet, built into the odds rather than billed separately. A true coin-flip market pays even money both ways; a standard -110/-110 line pays less either way, and that gap is the book's margin.
Why -110 Is Not a 50/50 Bet
Risking $110 to win $100 at -110 means breaking even requires winning over half your bets — about 52.4%, not 50%. That 2.4 points is the vig showing up as a win-rate requirement, not a fee charged upfront.
Turning Odds Into Implied Probability
American odds convert two ways: negative odds ÷ (odds + 100); positive odds, 100 ÷ (odds + 100). At -110 that is 110 ÷ 210, about 52.4%. Add both sides together and the total passes 100% — the excess is the vig.
Removing the Vig: What "Fair Odds" Look Like
Divide each side's implied probability by the sum of both sides for the "no-vig" probability — a way to judge whether a price is generous or thin.
Why the Vig Changes by Market
Spreads and totals usually carry the standard -110 vig. Moneylines on lopsided games often carry more, since pricing a heavy favorite precisely is harder. Player props and same-game parlays carry the highest margins of all.
Line Shopping Is How You Cut the Vig
The vig is not fixed industry-wide. One licensed book might offer -105 on a side another prices at -110 — a real cost difference, nothing about the game changed. Comparing prices before betting is the one lever a bettor has, covered further in our breakdown of reading American and decimal odds.
Where These Markets Are Legal
Licensed sports betting exists in US states with regulated online betting, in the UK under the UK Gambling Commission, and in Australia under state and territory licensing. Legal status changes as legislatures act, so confirm current rules where you live — and use books licensed in your jurisdiction. See our operator reviews for regulated books including DraftKings, FanDuel, and bet365.
You must be 21+ in the US or 18+ in the UK to bet legally. The vig is a built-in cost of every bet, not a signal about the outcome, and comparing prices never guarantees a win. If gambling stops being fun, see our responsible gambling page.
Want to see how the vig compounds across legs? Read our explainer on parlay odds and margin.
All content is fact-checked under our editorial standards.