I do the same as others on here. I add a about 4 to 7 years on everyone's age in the games.

How old was Cid in VIII supposed to be? I always put him in the mid to late 40's. They'll probably say he's 29 and call it ancient.

(SPOILER)Also, if we're divulging Vanille's real age, how old is Aerith from VII supposed to be? She is the last Ancient, after all.