User blog comment:Romerox/How many years will be calculated for each of the characters/@comment-24023034-20101117041643/@comment-71.0.220.225-20101226020326

Just because someone is taller, does NOT mean that they are older. Maybe he's older by a few months, but you have to take in that it is never said that Ferb is tall, just that Phineas is short (which is stated frequenty). But they are definetly the same age, not exactly, but they are the same age yearwise.