As many as you trainer(s) want you to. Or until they think you're ready.
2-5 years is the best.
4 years
A BS (RN) usually requires four years.
Zero Lots of luck, nospaces.
you just have to graduate high school
it dpends on ur smarts it could take 10 years 4 you to pass 1 class
Beauty schools generally take 6-9 months for training.
It will take up to six years to become a eye doctor. You can take double courses in order to complete within fours years instead of the six years.
Two years
A Bachelor of Science degree in education should take 4 years if you take a full load.
It depends on the individual, their expertise, experience, performance record etc.
It can take a person 9 months to 3 years to become a barber. You can check out http://degreedirectory.org/articles/How_Long_Does_it_Take_to_Graduate_from_Barber_College.html for more information.
If you are referring to a doctorate in terms of PhD, EdD etc., it would take approximately three to four additional years.