During the entire game, Crono's Age isn't stated even once.
When I was playing through it on the PSX, I felt as if the developers were trying to confuse my. At the start of the game, he get's an allowance from his mother, but at the end he gets married.
I'm sure that we can state he is young, due to the fact that he still lives at home. But during cutscenes, he looks quite mature.
Also, if you take a close look at certain art for Trigger, Crono looks like a young teenager, but in other parts resembles a grown man.
Any insight?