Movies are a major part of the entertainment industry, and their total box office collection is an important metric to measure the success of a film. To calculate the total box office collection, the amount of money the movie has earned from ticket sales, merchandise, and other sources is added up. This figure is then adjusted for inflation, currency exchange rates, and other factors to give a more accurate representation of the total box office collection. Additionally, the performance of the movie over time is considered, as well as its success in international markets. All of these factors combine to give an accurate picture of the total box office collection for a movie.