How long does it take to get a PHD or Doctorate in the sciences?

It completely depends on how you approach it.

A bachelor's degree will take 4-5 years, generally, unless you take a massively heavy courseload and finish in 3. (I advise against an overly-heavy courseload for the sake of your well-being. Some people can handle it, most will make themselves ill from stress.) A Ph.D. and doctorate are the same, by the way. :)

A Ph.D. after that (some people go for their master's and then Ph.D., some continue directly into a Ph.D. program) can take anywhere from 5-10 years on top of it. It generally goes like this:

• You decide to pursue a doctoral degree and, assuming you're admitted to the doctoral program, spend some time taking classes, usually about 3 years.


• You sit the candidacy exam to be designated a Ph.D. candidate. (If you hear students talking about Ph.D. quals, this is what they mean.) From what I know, if you fail this exam twice, you will usually not be allowed to continue in the program. Provided you pass, you are now a Ph.D. candidate.


• You'll spend the rest of the time preparing your dissertation, which is totally variable. The average is about 4-6 years. Some people take way longer, some blitz through it. It depends on what the subject is and what's required in doing the research. A dissertation is a huge research paper, essentially, that is a unique or new piece of work in the field. The final exam, so to speak, is your dissertation defense, where you defend your research in front of a committee of faculty and experts from the university. If you pass that (and most people do considering they've gotten that far!), you've fulfilled the requirements for graduating.

So from beginning to end, beginning of undergrad to Ph.D., usually about 14 years, give or take 3. I hope that helped!

Here's hard data: http://www.nsf.gov/statistics/infbrief/nsf06312/

TL;DR: Median time between completion of baccalaureate and PhD in 2003 was 10.1 years of which (on average) 7.5 years were actually spent enrolled in a PhD program, and the median age at doctorate was 33.3 years.

Of course, your mileage may vary...the median means half were longer and half were shorter than that.

EDIT: I had just grabbed the first search hit but there are newer surveys like this one: http://www.nsf.gov/statistics/sed/digest/2011/nsf13301.pdf , but a quote from that report says things haven't changed much: "Since 2006, however, there has been little change in the time to degree of doctorate recipients in S&E fields."