Mark Ruffalo was 46 in Avengers: Age of Ultron when he played the character 'Bruce Banner / The Hulk'.
That was over 8 years ago in 2015.
Today he is 55, and has starred in 84 movies in total, 23 of those since Avengers: Age of Ultron was released.
In Avengers: Age of Ultron, I think Mark Ruffalo looks: