It can be difficult to tell how old Superman is in the movies he’s been featured in over the years. Superman has many unique powers, including a much slower aging process. This superpower causes him to look around the same age in every film. Despite his youthful appearance, the movies have featured the Man of Steel at different points in his extended life. The James Gunn DCU movie Superman: Legacy reports making the DC hero younger than any movie to date, but this doesn't mean much for the appearance of the already youthful hero.

https://screenrant.com/superman-age-how-old-dc-movies/