How long does it take to get a PhD if you have a masters?

Answer 1

It depends on your field, where you go to school, and the requirements of your doctoral program.

For instance, doctoral programs in the humanities and social sciences often require you to have knowledge that isn't available in many undergrad programs, so a masters is more a requirement and doesn't reduce the time it takes for you to do your PhD. For example, I study Near Eastern history and needed to be able to read and write five phases of a dead language to be considered for the PhD program I ultimately completed. This meant I had to get a masters in a specialized field before I was able to apply to the PhD. In STEM fields, masters are less of a requirement for admittance to a PhD program, but again, that really depends on the specific field.

The average length of time for someone to complete a humanities/social science PhD in the US is around 10 years, though I think there's a big push to get that number down now. It's possible to finish a humanities/social science PhD in the US in as few as 5-6 years, though that's less common. A STEM PhD is more likely to take 5+ years in the US, but it largely depends on how long it takes for you to complete your research. In contrast, in the UK it generally takes someone 4-5 years to complete a PhD because there tend to be fewer degree requirements and they tend to be more research focused. In the US it's pretty standard to have ~2 years of coursework and 2-3 years of teaching as degree requirements regardless of if you have a masters or not, so that often slows your research progression down.