There are two ways of tracking the financial success of a movie. The first is to compare what a movie cost to make with its ticket sales based on the value of the dollar the year it was released. The other is to use inflation-adjusted numbers, which allows comparison between a movie made in 1939, for example, with one made today.

To determine the world’s highest-grossing movie of all time, 24/7 used the latter calculation. “Avatar” (2009) had inflation-adjusted ticket sales of $3.55 billion. (Without the adjustment, sales would be $2.8 billion, still very impressive)

“Avatar” is an unlikely candidate to be the highest grossing film. Written, directed, and produced by James Cameron, the science fiction movie takes place on a distant moon called Pandora in the middle of the 22nd Century. The movie stars Sam Worthington, Zoe Saldaña, Stephen Lang, Michelle Rodriguez, and Sigourney Weaver. (These are the best sci-fi movies of all time.)

There is a chance that the first of several planned sequels could make even more money than the first. Currently, “Avatar: The Way of Water,” released Dec. 14 of last year, has grossed just over $2 billion.

Here’s a list of the highest-grossing movies of all time.