For standard odds at -110, the vig is usually at 4.54 percent. A winning bet returns $210 for every $100 wagered ($110 + $100). The extra $10 has been kept by the sportsbook as vig - divide the $10 by the $220 wagered (total from a wager on both sides of -110) and the outcome is 4.54 percent. Vigorish/juice can also be calculated using the following formula: 100 * (1 – p * q/p + q). In this formula, p and q are the decimal payout (so the odds need to be converted to decimal).