PhD Failure Rate – A Study of 26,076 PhD Candidates


The PhD failure rate in the UK is 19.5%, with 16.2% of students leaving their PhD programme early, and 3.3% of students failing their viva. 80.5% of all students who enrol onto a PhD programme successfully complete it and are awarded a doctorate.


One of the biggest concerns for doctoral students is the ongoing fear of failing their PhD.

After all those years of research, the long days in the lab and the endless nights in the library, it’s no surprise to find many agonising over the possibility of it all being for nothing. While this fear will always exist, it would help you to know how likely failure is, and what you can do to increase your chances of success.

Read on to learn how PhDs can be failed, what the true failure rates are based on an analysis of 26,067 PhD candidates from 14 UK universities, and what your options are if you’re unsuccessful in obtaining your PhD.

Ways You Can Fail A PhD

There are essentially two ways in which you can fail a PhD; non-completion or failing your viva (also known as your thesis defence).


Non-completion is when a student leaves their PhD programme before having sat their viva examination. Since vivas take place at the end of the PhD journey, typically between the 3rd and 4th year for most full-time programmes, most failed PhDs fall within the ‘non-completion’ category because of the long duration it covers.

There are many reasons why a student may decide to leave a programme early, though these can usually be grouped into two categories:

  1. Motives – The individual may no longer believe undertaking a PhD is for them. This might be because it isn’t what they had imagined, or they’ve decided on an alternative path.
  2. Extenuating circumstances – The student may face unforeseen problems beyond their control, such as poor health, bereavement or family difficulties, preventing them from completing their research.

In both cases, a good supervisor will always try their best to help the student continue with their studies. In the former case, this may mean considering alternative research questions or, in the latter case, encouraging you to seek academic support from the university through one of their student care policies.

Besides the student deciding to end their programme early, the university can also make this decision. On these occasions, the student’s supervisor may not believe they’ve made enough progress for the time they’ve been on the project. If the problem can’t be corrected, the supervisor may ask the university to remove the student from the programme.

Failing The Viva

Assuming you make it to the end of your programme, there are still two ways you can be unsuccessful.

The first is an unsatisfactory thesis. For whatever reason, your thesis may be deemed not good enough, lacking originality, reliable data, conclusive findings, or be of poor overall quality. In such cases, your examiners may request an extensive rework of your thesis before agreeing to perform your viva examination. Although this will rarely be the case, it is possible that you may exceed the permissible length of programme registration and if you don’t have valid grounds for an extension, you may not have enough time to be able to sit your viva.

The more common scenario, while still being uncommon itself, is that you sit and fail your viva examination. The examiners may decide that your research project is severely flawed, to the point where it can’t possibly be remedied even with major revisions. This could happen for reasons such as basing your study on an incorrect fundamental assumption; this should not happen however if there is a proper supervisory support system in place.

PhD Failure Rate – UK & EU Statistics

According to 2010-11 data published by the Higher Education Funding Council for England (now replaced by UK Research and Innovation), 72.9% of students enrolled in a PhD programme in the UK or EU complete their degree within seven years. Following this, 80.5% of PhD students complete their degree within 25 years.

This means that four out of every five students who register onto a PhD programme successfully complete their doctorate.

While a failure rate of one in five students may seem a little high, most of these are those who exit their programme early as opposed to those who fail at the viva stage.

Failing Doesn’t Happen Often

Although a PhD is an independent project, you will be appointed a supervisor to support you. Each university will have its own system for how your supervisor is to support you, but regardless of this, they will all require regular communication between the two of you. This could be in the form of annual reviews, quarterly interim reviews or regular meetings. The majority of students also have a secondary academic supervisor (and in some cases a thesis committee of supervisors); the role of these can vary from having a hands-on role in regular supervision, to being another useful person to bounce ideas off of.

These frequent check-ins are designed to help you stay on track with your project. For example, if any issues are identified, you and your supervisor can discuss how to rectify them in order to refocus your research. This reduces the likelihood of a problem going undetected for several years, only for it to be unearthed after it’s too late to address.

In addition, the thesis you submit to your examiners will likely be your third or fourth iteration, with your supervisor having critiqued each earlier version. As a result, your thesis will typically only be submitted to the examiners after your supervisor approves it; many UK universities require a formal, signed document to be submitted by the primary academic supervisor at the same time as the student submits the thesis, confirming that he or she has approved the submission.

Failed Viva – Outcomes of 26,076 Students

Despite what you may have heard, the failing PhD rate amongst students who sit their viva is low.

This, combined with ongoing guidance from your supervisor, is because vivas don’t have a strict pass/fail outcome. You can find a detailed breakdown of all viva outcomes in our viva guide, but to summarise – the most common outcome will be for you to revise your thesis in accordance with the comments from your examiners and resubmit it.

This means that as long as the review of your thesis and your viva examination uncovers no significant issues, you’re almost certain to be awarded a provisional pass on the basis you make the necessary corrections to your thesis.

To give you an indication of the viva failure rate, we’ve analysed the outcomes of 26,076 PhD candidates from 14 UK universities who sat a viva between 2006 and 2017.

The analysis shows that of the 26,076 students who sat their viva, 25,063 succeeded; this is just over 96% of the total students as shown in the chart below.

Students Who Passed

Failed PhD_Breakdown of the extent of thesis amendments required for students who passed their viva

The analysis shows that of the 96% of students who passed, approximately 5% required no amendments, 79% required minor amendments and the remaining 16% required major revisions. This supports our earlier discussion on how the most common outcome of a viva is a ‘pass with minor amendments’.

Students Who Failed

Failed PhD_Percentage of students who failed their viva and were awarded an MPhil vs not awarded a degree

Of the 4% of unsuccessful students, approximately 97% were awarded an MPhil (Master of Philosophy), and 3% weren’t awarded a degree.

Note: It should be noted that while the data provides the student’s overall outcome, i.e. whether they passed or failed, they didn’t all provide the students specific outcome, i.e. whether they had to make amendments, or with a failure, whether they were awarded an MPhil. Therefore, while the breakdowns represent the current known data, the exact breakdown may differ.

Summary of Findings

By using our data in combination with the earlier statistic provided by HEFCE, we can gain an overall picture of the PhD journey as summarised in the image below.

DiscoverPhDs_Breakdown of all possible outcomes for PhD candidates based on analysis of 26,076 candidates at 14 universities between 2006 and 2017

To summarise, based on the analysis of 26,076 PhD candidates at 14 universities between 2006 and 2017, the PhD pass rate in the UK is 80.5%. Of the 19.5% of students who fail, 3.3% is attributed to students failing their viva and the remaining 16.2% is attributed to students leaving their programme early.

The above statistics indicate that while 1 in every 5 students fail their PhD, the failure rate for the viva process itself is low. Specifically, only 4% of all students who sit their viva fail; in other words, 96% of the students pass it.

What Are Your Options After an Unsuccessful PhD?

Appeal Your Outcome

If you believe you had a valid case, you can try to appeal against your outcome. The appeal process will be different for each university, so ensure you consult the guidelines published by your university before taking any action.

While making an appeal may be an option, it should only be considered if you genuinely believe you have a legitimate case. Most examiners have a lot of experience in assessing PhD candidates and follow strict guidelines when making their decisions. Therefore, your claim for appeal will need to be strong if it is to stand up in front of committee members in the adjudication process.

Downgrade to MPhil

If you are unsuccessful in being awarded a PhD, an MPhil may be awarded instead. For this to happen, your work would need to be considered worthy of an MPhil, as although it is a Master’s degree, it is still an advanced postgraduate research degree.

Unfortunately, there’s a lot of stigma around MPhil degrees, with many worrying that it will be seen as a sign of a failed PhD. While not as advanced as a PhD, an MPhil is still an advanced research degree, and being awarded one shows that you’ve successfully carried out an independent research project which is an undertaking to be admired.

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Additional Resources

Hopefully now knowing the overall picture your mind will feel slightly more at ease. Regardless, there are several good practices you can adopt to ensure you’re always in the best possible position. The key of these includes developing a good working relationship with your supervisor, working to a project schedule, having your thesis checked by several other academics aside from your supervisor, and thoroughly preparing for your viva examination.

We’ve developed a number of resources which should help you in the above:

  • What to Expect from Your Supervisor – Find out what to look for in a Supervisor, how they will typically support you, and how often you should meet with them.
  • How to Write a Research Proposal – Find an outline of how you can go about putting a project plan together.
  • What is a PhD Viva? – Learn exactly what a viva is, their purpose and what you can expect on the day. We’ve also provided a full breakdown of all the possible outcomes of a viva and tips to help you prepare for your own.

Data for Statistics

  1. Cardiff University – 2006/07 to 2016/17
  2. Imperial College London – 2006/07 to 2016/17
  3. London School of Economics (LSE) – 2006/07 to 2015/16
  4. Queen Mary University of London – 2009/10 to 2015/16
  5. University College London (UCL) – 2006/07 to 2016/17
  6. University of Aberdeen – 2006/07 to 2016/17
  7. University of Birmingham – 2006/07 to 2015/16
  8. University of Bristol – 2006/07 to 2016/17
  9. University of Edinburgh – 2006/07 to 2016/17
  10. University of Nottingham – 2006/07 to 2015/16
  11. University of Oxford – 2007/08 to 2016/17
  12. University of York – 2009/10 to 2016/17
  13. University of Manchester – 2008/09 to 2017/18
  14. University of Sheffield – 2006/07 to 2016/17

Note: The data used for this analysis was obtained from the above universities under the Freedom of Information Act. As per the Act, the information was provided in such a way that no specific individual can be identified from the data.


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