How long do you have to be in college for a doctorates degree?

Depends. For a doctorate in medicine, usually 4 yrs college, 4 yrs medical school, and 3-7 yrs in residency (post-graduated training). For a doctorate in other fields (phd), 4 yrs college, 2-4 yrs graduate school.
8 years. Approximately 8 years with some requiring an extra year or two depending on the pace at which some people take their course work.