This vig calculator takes the two prices on a line and shows how much the book keeps. Put in -110 on both sides and the answer is 4.55%: of every C$100 bet across that market, the book expects to hold about C$4.55. The free calculator also strips the vig out and gives the no-vig odds, which for -110/-110 is +100 each side, a true coin flip.
Vig calculator: what the numbers mean
Each price implies a chance. -110 means risking 110 to win 100, so you need to win 110 ÷ 210 = 52.38% of the time to break even. Both sides at -110 add up to 104.76%. That extra 4.76% is the overround. The vig, also called the juice or the hold, is the slice of a balanced book the bookie keeps:
Implied chance = 1 ÷ decimal odds Overround = chance A + chance B (+ draw) Vig (hold) = 1 − 1 ÷ overround No-vig odds = decimal odds × overround
For -110/-110 that’s 1 − 1 ÷ 1.0476 = 4.55%. Two numbers, 4.76% and 4.55%, for the same line. They’re both right; they just divide by different things. Most people in North America quote the hold, so that’s what the calculator puts first, with the overround underneath.
Lines and their juice
A few common two-way lines, so you know what a normal price looks like:
| Line | Vig | No-vig odds | Break-even |
|---|---|---|---|
| -105 / -105 | 2.38% | +100 / +100 | 51.22% |
| -110 / -110 | 4.55% | +100 / +100 | 52.38% |
| -115 / -105 | 4.50% | -104 / +104 | 53.49% / 51.22% |
| -120 / +100 | 4.35% | -109 / +109 | 54.55% / 50.00% |
| -150 / +130 | 3.36% | -138 / +138 | 60.00% / 43.48% |
| -120 / -120 | 8.33% | +100 / +100 | 54.55% |
The bottom row is the one to watch for. Plenty of player props and alternate lines sit at -120 on both sides, nearly double the juice of a standard spread, and it’s easy not to notice because -120 doesn’t look much worse than -110.
What the vig costs you
Bet C$100 a game at -110 and, if you’re exactly as good as a coin flip, you lose about C$4.55 a bet on average. Over a 17-week football season at five bets a week that’s roughly C$390 gone to the juice before your picks have done anything. That’s why the average vig output is there: put in your usual stake and see it in dollars.
It’s also why shopping lines matters. Find -105 instead of -110 on the same side and the break-even rate falls from 52.38% to 51.22%. Over a few hundred bets that’s the difference between a break-even bettor and one who’s slightly up.
No-vig odds and spotting value
The no-vig price is your best guess at the real odds. If a sharp book has a game at -150/+130, the no-vig price is about -138/+138. Another book offering +150 on the underdog is paying more than the fair price, and that’s a bet with value. The calculator uses the proportional method, which spreads the vig evenly across both sides. On lopsided lines books often load more of it onto the longshot, so the favourite’s real price may be a touch shorter.
For markets with more than three outcomes, a horse race or a futures market, the bookmaker margin calculator takes up to 20 prices. The odds converter switches between American, decimal and fractional, and if the implied chances across two books ever add up to less than 100%, the arbitrage calculator works out the stakes. Teasing the line instead? The teaser calculator shows the break-even rate per leg.
Want a different de-vig method? The no-vig calculator also does additive and power de-vigging, and tests any price against the fair line.
Low juice makes a bet cheaper, not a winner. If it stops being fun, BeGambleAware.org can help.