To calculate potential profit in spread betting, you need to consider the odds offered by the bookmaker, your stake, and the outcome of the event. Let's assume a basketball game has a favorite with a -4.5-point spread with odds of -110. If you bet $110 on the favorite, you would win $100 if they win by more than 4.5 points, plus your original stake. If they don't, you lose your initial bet. The same applies to underdog wagers, where your potential profit depends on the odds and your stake.