How Long Does It Take To Get a PhD?

A PhD, or doctorate degree, is the highest degree you can earn in certain disciplines, such as psychology, engineering, education, and mathematics. As a result, it often takes longer to earn than it does for a bachelor’s or master’s degree.

While many PhD programs are designed to be finished in four or five years, the average completion time is much longer when you factor in the time it takes to research and write a dissertation. In 2020, for example, doctoral students took between six and twelve years to complete their PhDs [1]. By comparison, you can complete a master's degree in one to three years.

In this article, we'll 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.

PhD requirements + general timeline

Doctoral programs typically require PhD candidates to take take advanced courses, pass a comprehensive exam (sometimes called "comps"), and produce an original body of research, such as a dissertation, to obtain the degree. In some cases, 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.

PhD requirements

The precise requirements you'll need to complete in order to get your PhD vary from one program to another, but some common tasks include:

• 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

PhD timeline

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.

Note that while this timeline gives a general timeline of how long it will take to complete a PhD program, it's very common for candidates to take more than one year to research and compose their dissertation.

Read more: Should You Go Back to School? 7 Things to Consider



PhD timelines by focus

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) [1]. 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?

Why does it take so long to complete a PhD?

There are a few reasons why it takes more time to complete a PhD compared to other advanced degrees.

1. Dissertations

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 [2].

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.

2. Assistantship obligations

Teaching and research assistantships are beneficial because 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 that students have as part of their assistantship, 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 institution's financial support and the reduced number of classes students taught [3].

3. Other responsibilities

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 [4]. In effect, 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.

Is a PhD right for you?

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 your best choice.

If your career aspirations don't require a PhD, it might be better to 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?

Benefits of a PhD

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 [5]. 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 and the fortitude to finish such an advanced degree.

Costs of a PhD

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 even exceed $200,000 [6]. While many institutions offer funding support in the form of assistantships or scholarships, many PhD students still graduate with student loan debt. In 2023, the average student loan debt for PhD was $134,797 [7].

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 [8].

Read more: How to Pay for Graduate School: 8 Ways

Set yourself up for success

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 [9]:

1. Understanding the demands and expectations of the program

2. Receiving adequate program orientation

3. Getting support from peers and faculty

4. 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.

Next steps

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.