The most common aspect ratio for movie screens is 1.85:1 to 2.35:1. The filmmakers decide the aspect ratio of a film and preferences differ from director to director. Often larger epic films, such as Gladiator, Titanic, and Star Wars are filmed with the wider scope of 2.35:1 to create a sense of being larger-than-life. Smaller, more personal films tend to favor the less gigantic 1.85:1 ratio. But what would be the actual size of an average movie screen? I would say 30-foot by 70-foot.