Usually, it's 5 years for BA, 2-3 for MA these days. I was the youngest grad student in my first and I believe second years in my program. Conversely, if I had stayed in my program and earned my Ph.D. after 3-4 years, I would have been way ahead of the curve, since there usually aren't many Ph.D.'s at 25-26. But I burned out due to taking so many classes in so short of a span, coupled with being only 17 when I registered for classes my first year of undergrad classes.

And if I were to look at that joke called a grad degree in Education, well...the age is skewed even higher than it is in History and most other fields.