How many pages of dialog are needed to create a feature film?

Proper screenplay format dictates that one page of a screenplay equals 1 minute of movie. Movies generally average 90 minutes to 120 minutes so between 90 to 120 pages.

If you don't know how to properly format a screenplay I would suggest getting a book on screenplay writing to familiarize yourself.

On average the rule of thumb is one minute per page of screenplay. This of course can vary greatly based on how much dialogue, direction and description appear in the screenplay.

The term feature length varies in meaning. I think the Academy defines it as over 40 minutes. Most people define it as over 60 minutes or over 80 minutes.

Most producers like the screenplay to be longer than the film is planned for. They would rather shoot a screenplay that is 200 pages to get a 120 minute film. This is so they have plenty of material and it can be edited down to a tight well greased production in editing.

Of course, these are just general guidelines about how it works. There have been feature length films shot with very short screenplays, or even no screenplays.