The first step is to convert the odds to implied probability as suggested by the sportsbook. To bring some perspective to the equation we can use a real sample NBA game between the Chicago Bulls vs Toronto Raptors, whereby the odds are set at +210 (32.26%) and -250 (71.43%) respectively. The last step is to take away 100% from the total and the percentage you are left with is the vigorish. You then need to add the percentages together to get the total. First, you need to convert the sportsbook odds into implied probability for every possible outcome (home-win, tie, away-win – 1×2), or use an odds-probability comparison table. Outcome odds probability + Outcome odds probability – 100% = Vigorish. However, you can calculate vigorish on every betting line whether you are wagering on the NBA, NCAA or other sport using a simple equation:
The cost of sports betting vig can vary from market to market and from one sportsbook to another.
