In the the US the PhD is normally part of the masters program (MS/MA) which is earned at the same institution. Usually this takes two years after undergrad. So

In the the US the PhD is normally part of the masters program (MS/MA) which is earned at the same institution. Usually this takes two years after undergrad. Some can a five year accelerated undergrad + masters, and there are people that finish undergrad in three years. However even then they will want you take take additional courses at the same institution, so it would often be a wash. In experimental science, the PhD phase after masters typically takes three to five years. So a total of seven years for MS + PhD would not be unusual. For other programs, such as math and humanities, it is normally shorter, but less than five years for masters + PhD would be unusual.