Question: how old are snk characters?
Answer: For the main cast of the 104th: Eren, Mikasa, Armin, Connie, Christa, and Jean are 15. Bertoldt, Annie, Marco, and Sasha are 16. Ymir and Reiner are unknown, I'd say they're either 16 or 17. None of the adults have official ages as far as I can tell (excluding Levi).