If a movie released in theatres fails to break even by a significant amount, it is termed a bad box office or box office failure, and the distributor, studio, and/or production firm that invested in it loses money. Because of the secrecy surrounding the film industry’s expenditures and profit margins, numbers of losses are at best approximations, and there are frequently differing estimates of how much a film has lost. Where this is the case, the losses are shown as ranges, and the list is alphabetically arranged in the lack of a definitive order.
Because the films on the list were released over such a long period of time, currency inflation had to be factored in, therefore the losses were adjusted for inflation using the US Consumer Price Index to ensure a fair comparison.
Even if several of the films on this list made more money than their production expenses, they are still considered failures. This might be owing to Hollywood accounting techniques, which generally manipulate earnings or keep costs hidden to avoid profit-sharing agreements, but films can sometimes lose money legitimately even when the box office gain surpasses the budget. This is due to the fact that a distributor does not get the entire gross, and the total cost of a film can easily surpass its production budget after distribution and marketing are factored in.
When ancillary income, such as home media sales and rentals, television broadcast rights, and licencing fees, are included in, a corporation may benefit from a box office disaster in some instances, thus a picture that loses money at the box office may eventually break even.