How long does it take to complete 65 credit hours as a full time student?

It will take approximately two years. You might be able to cut off one semester by taking summer and interim sessions (if the curriculum allows it).

It took me 1 1/2 years to get 65 credit hours. I go to community college and it depends on how high the grade is you receive for the course. For instance I had a b in one class and received 9 credit hours for it and I had an a in another 3 cred class and got 12 credit hours for it. If your school runs that way this is how you accomplish that many credit hours in a little bit of time.