Sportsbooks don’t post the true price of a bet—they post one with a margin baked in so they profit no matter which side wins. That margin is the vig, and it shows up as the two sides’ implied probabilities adding up to more than 100%. This calculator removes it: it converts each side to an implied probability, rescales the two so they total exactly 100%, and turns those fair probabilities back into odds.

Enter the price on both sides of a market and you’ll get the fair, no-vig odds plus the true win probability for each. For example, a market of -150 / +130 implies about 60% and 43.5% (103.5% together); strip the 3.5% vig and the fair line is roughly -138 / +138, or 58% / 42%. When a book’s actual price beats the fair number, the bet is +EV.