5 tips for passing your PhD viva

Essential tips for passing your PhD viva

1. Understand how the viva will run on the day

Before your viva, take time to understand how the conversation about your research will work so nothing is too unfamiliar on the day.

You should:

• confirm whether your viva is in person, online or a mix of the two
• check the structure and format used by your university
• understand who will be in the room and their roles.

Many universities provide detailed guidance. For example, the University of Oxford outlines the typical sequence of a viva, while The University of Manchester offers candidate guidance on what examiners expect.

2. Be ready to explain and justify your research

Remember that your examiners aren't testing your memory - they want to understand how and why you carried out your research.

Focus on being able to clearly explain:

• how your work fits into the wider field
• what your research adds or changes
• why you chose your research topic and methods.

A helpful approach is to prepare short explanations of key sections, such as:

• your research question
• methodology
• main findings.

Many institutions, including University College London (UCL), advise candidates to approach the viva as a discussion of their academic judgement.

3. Practise answering questions out loud

You'll perform more confidently if you've already practised explaining your work verbally.

Try to:

• give clear, concise responses
• organise a mock viva with your PhD supervisor or peers
• run through answering common questions aloud.

For example, universities such as the University of Leeds often encourage a mock viva as part of Doctoral training programmes.

When rehearsing your responses:

• allow room for natural discussion rather than memorised answers
• avoid over-explaining
• stay focused on the question.

4. Research your examiners and position your work

Understanding your examiners' academic interests can help you anticipate how they might approach your thesis.

Before the viva:

• identify where your work aligns or differs
• review their published research
• think about how you would respond to different viewpoints.

For instance, guidance from institutions such as the University of Cambridge advises candidates to be aware of how their research fits within current academic debates.

5. Plan your final preparation and approach on the day

In the final weeks, focus on practical preparation to stay calm and organised.

Leading up to your viva:

• plan the logistics (travel or online setup)
• prepare any notes or annotated copies
• schedule time to review key sections of your thesis.

On the day:

• pace yourself - the discussion can be lengthy
• support your points with examples from your thesis
• take time to think before answering.

It's important to plan and manage your time effectively before the viva, so get more general advice on preparing for an interview.

You can also be ready for an online PhD viva by reading our video interview tips.

How to prepare for your PhD viva

How is the viva assessed?

Your viva is assessed by at least two examiners (an internal and an external), who evaluate both your written thesis and your ability to discuss it in depth.

They're looking for evidence that your work is:

• able to make a clear contribution to your field
• academically rigorous
• original.

Rather than testing memory, the viva focuses on your:

• understanding of your research decisions
• findings
• their wider significance.

How long does the viva last?

A PhD viva typically lasts between one and four hours, although most take around two hours depending on your subject and the scope of your research.

The length can vary based on how much discussion your thesis generates and whether examiners want to explore certain areas in more detail. For example, they can be:

• Short (45 to 90 minutes) - typical length in computer science, maths and some science disciplines where the discussions can be highly technical, specific, and rigorous with numbers. It can just mean that the examiners are highly satisfied with your thesis.
• Average (one to three hours) - this is the most common standard across UK universities, including The University of Manchester and the University of Sheffield. It allows time for a brief introduction, page-by-page review, and exploration of the methodology. If it passes the two-hour mark, a break is usually recommended.
• Long (three to four hours) - more common in the humanities and social sciences, this longer time is often not a worrying sign. Examiners tend to use this additional time for a rounded discussion about your academic journey, future publications, and the wider implications of your work.

Who conducts the viva, and who will be there on the day?

Your viva is typically conducted by two examiners, including an:

• internal examiner from your university
• external examiner from another institution.

A chair may also be present, and in some cases, your PhD supervisor can attend with your permission.

Do all PhD students have to do a viva?

Yes, most PhD programmes require a viva as a standard part of assessment. It allows examiners to confirm that the work is your own and that you fully understand your research.

It's a key step in demonstrating your ability to defend your findings and contribute to your subject area.

What should I wear to the exam?

There's no strict dress code, but it's best to wear something smart and comfortable that helps you feel confident and professional. This also applies to online vivas.

Can I bring notes?

Yes, you're usually allowed to bring a copy of your thesis, notes or annotated sections to refer to during the discussion.

This can help you navigate your work and stay focused if you need time to think through your answers.

What questions are likely to be asked by the examiners?

• What original contribution has your thesis made to this field of study?
• Explain the main research questions you were hoping to address.
• What are the strengths and weaknesses of your thesis?
• If you had to start the thesis again, what would you do differently?
• If funding were no object, describe how you'd follow on from this project.
• What are your plans after graduation?

Is there anything to avoid doing?

Avoid overly long or unfocused answers, as this can lead to additional questioning in areas where you're less prepared. It's also important not to memorise responses word for word - examiners are looking for genuine understanding rather than rehearsed answers.

If you don't know an answer, it's better to acknowledge this and explain your thinking than attempt to guess.

What are the possible outcomes of a viva?

Can I fail my viva?

Failing a viva is extremely rare. Most candidates either pass outright or are asked to make minor corrections to their thesis before it is formally accepted.

In some cases, more substantial revisions may be required, but outright failure is uncommon.

How and when do I get the results?

In most cases, you'll receive an initial verbal outcome shortly after the viva, followed by a formal written report outlining any required corrections.

The final award is confirmed once any revisions have been completed and approved.

Can I appeal the result?

Yes, universities typically provide an appeals process if you believe there has been a procedural error or unfair treatment during your assessment.

Appeals must usually be made within a specific timeframe, typically within 10 to 14 days, and supported by evidence.

To discover what this means for you, check your institution's viva process and regulations.

Find out more

• Explore possible careers after completing your PhD.
• Consider getting an academic job.
• Read our essential guide to PhD study.