A PhD, or doctorate degree, is the highest level of degree you can earn in certain disciplines, such as psychology, engineering, education, and mathematics. As such, it often takes longer to earn than a bachelor’s or master’s degree.
While many PhD programs are designed to be finished in four or five years, the average time to completion is actually much longer when you factor in the time it takes to research and write a dissertation. In 2020, doctoral students took between six and twelve years to complete their PhD . By comparison, you can complete a master's degree in one to three years.
Let’s explore the requirements of a PhD, what often ends up adding to the length of time, and important factors you should consider when deciding whether it’s the right choice for you.
Doctoral programs typically include taking advanced courses, passing a comprehensive exam (sometimes called "comps"), and producing an original body of research, such as a dissertation. You may also be expected to fulfill a teaching assistantship or research assistantship, both of which are meant to prepare you for a career in academia or research.
Advanced coursework: Graduate-level coursework that explores a number of advanced sub-topics related to your field
Comprehensive exam: An exam that requires you to show knowledge of your field, such as its history, important figures, major theories or research, and more
Dissertation: An original body of research you contribute to your field
The specifics of a PhD program vary by college and university, but the following estimates give you an idea of what to expect during your time in graduate school:
Year 1: Complete advanced coursework.
Year 2: Complete advanced coursework and begin preparing for your comprehensive exams.
Year 3: Study, take, and defend your comprehensive exams. Begin researching your dissertation proposal.
Year 4: Submit your dissertation proposal to your committee chair, and, once approved, begin working on your dissertation.
Year 5: Finish writing your dissertation and submit for committee approval. Defend your dissertation and apply for graduation.
Some PhD programs take longer to complete than others. For example, earning a doctorate in a science and engineering field typically takes less time than earning a doctorate in the arts or humanities, according to data from the National Center for Science and Engineering Statistics (NCSES) . The list below shows the median length of time it took doctorate students to earn their degree in 2020:
Physical and earth sciences: 6.3
Engineering: 6.8 years
Life sciences: 6.9 years
Mathematics and computer science: 7 years
Psychology and social sciences: 7.9 years
Humanities and arts: 9.6 years
Education: 12 years
Learn more: What Is a Terminal Degree and Do I Need One?
There are a few reasons why it takes more time to complete a PhD compared to other advanced degrees.
Once a doctoral student has successfully passed their comps, they are considered “All But Dissertation” or “ABD.” Yet, the number of students who successfully complete their PhD program remains low—estimates show that nearly 50 percent of students drop out, often after reaching the dissertation phase .
The dissertation phase can often take much longer to complete than the other requirements of a PhD. Researching and writing a dissertation takes significant time because students are expected to make an original and notable contribution to their field.
Teaching assistantships and research assistantships are beneficial in that they can help pay for a PhD program, but they may also take time away from working on your dissertation. Some students are expected to teach at least one class per semester on top of their other obligations as graduate students.
For universities that reduce the teaching or research load students have as part of their assistantship, the times to completion tend to improve. Humanities students at Princeton University began finishing their degree in 6.4 years (compared to 7.5 years) thanks to the financial support the institution offered and the reduced number of classes students taught .
Doctoral students tend to be older. Graduate students pursuing a PhD in science or engineering were an average of 31.6 years old by the time they earned their degree in 2016, according to the National Science Foundation . As such, some PhD students may have competing obligations, such as family. If a student’s funding has run out, and they have to find full-time work, it also may affect the time they can dedicate to writing their dissertation.
People pursue PhDs for various reasons: Some want a job that requires the degree, such as teaching at a university, while others want the challenges or intellectual engagement that a graduate program offers. Identifying why you want to earn a PhD can help indicate whether it’s the best choice for you.
If your career aspirations don't require a PhD then it might be better if you focus on gaining professional experience. Or if you're interested in an advanced education, a master's degree may be a better option. It takes less time to complete than a PhD and can lead to more career opportunities and larger salaries than a bachelor's degree.
Learn more: Is a Master’s Degree Worth It?
The primary advantage of earning a PhD is your increased demand and marketability in the workforce. In 2018, less than 5 percent of the United States population had a doctorate degree, compared to about 48 percent with a bachelor's degree and 21 percent with a master's degree, according to the US Census Bureau . As a member of this elite group, the potential for advanced roles, promotions, or pay raises may be greater.
Even before you have a degree in hand, working toward a PhD gives you opportunities to hone valuable skills, including writing, research, and data analysis. Furthermore, completing a PhD program can demonstrate to potential employers that you have specialized knowledge—as well as the fortitude to finish such an advanced degree.
Beyond the time they take to complete, PhD programs can be expensive. The average cost of a PhD program in the United States is just under $100,000. At some schools, the cost of a PhD can exceed $200,000 . While many institutions offer funding support in the form of assistantships or scholarships, many PhD students still graduate with student loan debt. In 2021, the average student loan debt for PhD was $159,625 .
Another factor to consider is the loss of income you might incur while you're working toward your degree. Some graduate students accept teaching or research assistantships to help fund the cost of their program, but these may not pay as much as full-time positions. Working on your education may also mean pausing the professional experience you’d gain in the workforce—and potentially losing out on promotions and raises. However, it’s worth noting that graduate degree holders earn much more over the course of their lifetime than bachelor’s degree holders, according to the US Social Security Administration .
A PhD is a major accomplishment. As you think about your long-term goals and whether a PhD will help you achieve them, it's important to understand ways you can set yourself up for success. According to the University of Georgia, success in a PhD program often means :
Understanding the demands and expectations of the program
Receiving adequate program orientation
Getting support from peers and faculty
Feeling a sense of belonging as a member of an academic community
These conditions underscore the importance of choosing the right program and school to fit your personal and professional goals. Take time to research the ways your potential institution offers financial support, mental health support, and career placement support, among other program features.
An advanced degree can be a lucrative credential. You can earn your master’s in a number of in-demand fields from top universities on Coursera. Earn a degree in computer science, business, management, or public health, all while enjoying greater flexibility than an in-person degree program tends to offer. Earning your master's can also help you discern whether a PhD makes sense for your larger objectives.
1. Survey of Earned Doctorates. "Path to the doctorate, https://ncses.nsf.gov/pubs/nsf22300/report/path-to-the-doctorate." Accessed January 20, 2022.
2. International Journal of Higher Education. “Who Are the Doctoral Students Who Drop Out?, https://files.eric.ed.gov/fulltext/EJ1188721.pdf.” Accessed January 20, 2022.
3. The New York Times. "Exploring Ways to Shorten the Ascent to a PhD, https://www.nytimes.com/2007/10/03/education/03education.html." Accessed January 20, 2022.
4. National Science Foundation. "Science and Engineering Doctorates, https://www.nsf.gov/statistics/2018/nsf18304/report/age-at-doctorate-award-what-are-the-overall-trends-and-characteristics/characteristics-of-doctorate-recipients-sex.cfm." Accessed January 20, 2022.
5. US Census Bureau. "About 13.1 Percent Have a Master’s, Professional Degree or Doctorate, https://www.census.gov/library/stories/2019/02/number-of-people-with-masters-and-phd-degrees-double-since-2000.html." Accessed January 3, 2022.
6. Education Data Initiative. "Average Cost of a Doctorate Degree, https://educationdata.org/average-cost-of-a-doctorate-degree." Accessed January 3, 2022.
7. Education Data Initiative. "Average Graduate Student Loan Debt, https://educationdata.org/average-graduate-student-loan-debt." Accessed January 20, 2022.
8. Social Security Administration. "Education and Lifetime Earnings, https://www.ssa.gov/policy/docs/research-summaries/education-earnings.html." Accessed January 20, 2022.
9. A Data-Driven Approach to Improving Doctoral Completion. "Chapter 2: Description of Projects, https://cgsnet.org/cgs-occasional-paper-series/university-georgia/chapter-2." Accessed January 3, 2022.
This content has been made available for informational purposes only. Learners are advised to conduct additional research to ensure that courses and other credentials pursued meet their personal, professional, and financial goals.