How long does it take to obtain a Ph.D?

Anywhere from 4 to 7 or more years after you get your bachelor’s degree. It all depends on the time it takes to finish your coursework and then do your dissertation which will usually involve massive amount of research, writing and revision.

I have seen people do it in anywhere from 3 to 8+ years, depending on the field. The guy who did it in 3 was a special case and had already done most of the work he needed to before formally joining the program. In the other extreme, there are people in the classics department at my school who are into their 10th year or so.

On average, most people in my department take six years.

my wife got hers in three years after her masters

Depending on what your degree will be in you can do the course work in as little as four semesters. The doctorate can take anywhere from two to six years to complete.

In the UK it depends upon your institution but in my case I had 3 years to submit after my 3 years of research i.e. 6 years from the start of the research period. I needed it all whereas my colleague who worked along side of me had an easier time of it and submitted within 6 months of his research finishing. Then there comes the viva!

From what I know, I agree with @AstroChuck…But you need to get a bachelors degree (3–5 years) and masters degree (2 years) first before anyone will let you attempt a PhD. At this point, I probably wouldn’t bother with a PhD unless I wanted a career in academia. And then you’re fighting increasingly more competitively for few positions and if you make it that far, slaving for tenure. It does seem like a cushy lifestyle in the later years though.

@lilikoi: You don’t need a masters degree. Some programs include a masters on the way to the PhD; others skip it completely.

After you get your masters degree, it could be anywhere from four to 10 years. I don’t know anyone who has done it in less than four or who took more than 10 years.

@nikipedia That’s a really good point.. I’ve only heard of JD programs being that way (where you’re required to have a bachelor’s but skip the master’s). Are there others? I guess it varies by university… At our local uni, the architecture program was doctorate only for the longest time – no Bachelor’s, no Master’s, 7 year program that accepted kids straight from high school. They just changed it to a more traditional B / M / PhD program with varying time commitments to each.

@Jelly I guess it would help to know what field you’re talking about…

It depends on the field, school, and the facilities of the university where you’re studying. My mother is getting her PhD in marine fisheries. She’s been working on it for 4 years and probably will not complete it for another 2 more years.

In my case, it’s 33 years and still counting. I did the same thing that Brian May (of Queen) did; started the program, went off and had an unrelated career, now I’m back at it. I’d done two years post MA before I joined the Army. I’m about a years full-time work away from a PhD in history, but only spending about a quarter of my time on it now. Adding it all up, it will be about five years equivalent full-time work.