From Detective Conan Wiki
Shinichi enters Pre-School
Shinichi enters Pre-School.
Shinichi enters Elementary School
Shinichi in Elementary School.
Shinichi enters Middle School
Shinichi on the soccer team 4 years ago.
Shinichi at the ski slopes 3 years ago.
Shinichi enters High School
Shinichi's first case 1 year ago.
The Manga, as Conan, He almost tells Ran that he is currently 16, but corrects himself to say that he is 6 (Ch002, Jan 1994).
The Anime ignored the above fact and has Shinichi say he is 17 in the opening (episode 003, Jan 1996)
The Manga, A news reporter mentions Shinichi's age as 16 again (Ch139, Dec 1996)
The Movies ignore this even further by having Shinichi's birthday occur after the anime gave the wrong age (Movie 1, Apr 1997)
Shinichi is listed as a second year High School student by his character text box
Shinichi's original Manga appearance. Shinichi's original Anime appearance.
