September 16, 2026
What Is the Vig? How to Calculate No-Vig Odds by Hand
The vig explained: how the margin hides inside -110 odds, how to strip it out for fair no-vig odds, and a ready-made list for the lines you see most.
The vig is the book's cut, baked into the odds before you ever see them. Nobody sends you an invoice for it. It simply means that if you added up the chances implied by every price in a market, you'd get more than 100%, and that surplus is how a sportsbook gets paid.
You'll hear it called vigorish, juice, margin or overround. Same thing each time. Most bettors never work it out, and for a small bet on a Sunday that's fine. It starts to matter once you bet regularly, because the vig is the one cost you pay on every single bet, win or lose. This page shows you how to spot it, how to take it out of any price, and why it's bigger than it looks.
What is the vig in betting?
Start with the classic American line, -110 on both sides of a game. Picture two friends who can't agree on the result, and each puts $110 on their side. Whoever's right gets $210 back, their own stake plus $100 of winnings.
Count it up and the book has $220 in and $210 out. It has pocketed ten dollars without needing to know a thing about football. That tenner, a bit over 4.5% of what came in, is the vig on a standard -110 game. No wonder books love it when both sides get backed equally.
How to see the vig in any odds
Every price hides a probability, and pulling it out gets quick after the second go:
Decimal odds are the easy ones. Divide 100 by the price and 1.91 turns into roughly 52%.
Minus numbers such as -110 go over themselves plus 100. So it's 110 over 210, and you land on the same 52-and-a-bit percent.
Plus numbers flip it. +150 becomes 100 over 250, which is a 40% chance.
Do that for both halves of a -110 game and you're holding two lots of 52.38%. Together they make 104.76%, and the two sides of a fair coin flip can't add up to more than 100. Those extra 4.76 points are the overround, and expressed as a share of the money they bring you back to the 4.55% hold.
How to calculate no-vig odds
No-vig odds, sometimes called fair odds, are what the prices would be with the margin removed. Four steps get you there, and a phone calculator is plenty.
Here's a real example. On 16 September our board had Buffalo at 1.42 and Detroit at 2.80 to win their game the following night.
First, turn both prices into chances. Buffalo at 1.42 is telling you about 70%, and Detroit at 2.80 about 36%. Neither is fair yet, and the next step shows why.
Add the pair and you get roughly 106.1%. That's six points too many, and those six points are the overround on this game.
Shrink both back so they total 100. Buffalo's share becomes about 66.4% and Detroit's about 33.6%: same proportions, padding removed.
Last, flip them back into odds by dividing 1 by each chance. Buffalo comes out near 1.51 and Detroit close to 2.97, or about -197 and +197 if you think in American odds.
So the fair price on Detroit was around 2.97 and the board offered 2.80, while Buffalo's fair 1.51 was trimmed to 1.42. Those two gaps are the vig, shaved off both sides of the same game.
This is the simplest way to share the margin out, in proportion to each price. Most no-vig calculators use it unless you tell them otherwise, and for everyday decisions it's perfectly fine.
No-vig odds for common lines
Rather skip the arithmetic? These are the fair versions of lines you'll run into all the time. Chances are rounded, and the hold is what the book keeps from balanced action:
-110 / -110. Once the vig goes it's 50% each and even money both ways. The 4.55% hold here is the one everyone quotes.
-115 / -105 is only a slight lean, about 51% against 49% underneath, so -104 and +104 fair, with 4.50% held.
-120 / +100. Underneath sits 52.2% versus 47.8%, roughly -109 and +109, and a 4.35% hold.
-130 / +110 hides a 54-46 split. Call it -119 and +119 fair; the book keeps 3.98%.
-150 / +130 is where a clear favourite starts showing, 58% against 42%. Fair is about -138 and +138, and 3.36% is held.
-200 / +170. Roughly 64 against 36, which means -180 and +180 without the margin. Hold: 3.57%.
-300 / +240 is a heavy favourite at nearly 72%, and stripped of margin that's -255 and +255 with 4.23% going to the book.
Notice the fair American numbers mirror each other. That's the tell that the margin is gone, because a fair two-way market leaves no edge for either side to pay.
Three-way markets work the same way
Football has the draw to deal with, so there are three prices instead of two. Nothing else changes.
A fairly ordinary match might be home 2.10, draw 3.40, away 3.60. Convert those and they add up to roughly 104.8%, so close to five points of margin are shared across the three results. Take it out and that home win is really worth something nearer 2.20.
Why the vig matters more than it looks
A few percent sounds harmless. Then you look at what it does to the break-even rate.
Here's the bit that stings. At -110 you need to win a little over 52 bets in every 100 just to break even. Win exactly 50 and you're down about $500 for every $11,000 you've put through, which is a lot to pay for being bang average. At -120 the bar goes up again, to nearly 55 in 100.
Parlays make it bigger, because each leg carries its own margin and the parlay multiplies them. Our parlay guide works through a three-leg ticket where around 6% on each leg turns into about 16% on the whole thing.
Markets with lots of runners, like season futures or a golden boot list, usually carry far more total margin than a simple two-way line. Always add them up before you decide a long price is generous.
How to use no-vig odds when you bet
Fair odds give you a benchmark. The useful question is never whether a price looks big, it's whether the price is bigger than your own honest estimate of the chances.
Say you think Detroit win that game 40% of the time. Your fair price would be 2.50. The board's 2.80 is longer than that, so each dollar staked would, by your numbers, be worth about $1.12. That's value, and it only holds if your 40% is right, which is the hard part nobody can do for you. Nobody gets every estimate right, including the people setting the lines, and that's what keeps the whole thing interesting.
Run the same check on spreads. Our spread betting guide reads the margin off three real handicap lines from that game, and it's the same four steps.
When you're ready to test a number against the board, open the sportsbook and switch Odds Format at the bottom to American or decimal, whichever you do the maths in. Tennis is a good place to practise, since most matches are simple two-way markets, and our tennis betting guide explains the main ones.