Generally, a screenplay should be 90 to 115 pages long. An old practice followed by world-famous filmmakers is that for a screenplay of a standard format, one page of the script equals to one minute of screen time. According to this standard, a 90-page screenplay will likely result in a 90-minute long film.

Although this formula is in practice for quite long, we must keep in mind that this may not produce exactly the same results as measured in all cases. It is because sometimes an action within a scene may require longer description in print than it would take on-screen.

So, in principle, the script should not exceed 115 pages. Making the screenplay 120 pages and beyond is considered to be too long. Yet, if the story is based on or contains scenes with long conversations, it may take some extra pages.