If you’ve ever found yourself wondering, “How long does it take to get a PhD” you’re not alone. Before I started mine I thought I’d be working right up until the university’s four year deadline to submission. However it is often possible to submit a PhD faster, though you do have to consider the time for your viva and corrections.
In this post we’ll go through each of the different stages of a PhD. We’ll also look at how much time a PhD takes up in the wider context of your career as a whole.
At the end you can find a timeline showing how long I personally took to go through each stage on the journey to getting my own PhD!
How long does it take to get a PhD when studying full time?
In short, full-time PhD students in the UK will typically take 3-4 years to submit their PhD thesis. Then it’s a few more months before the viva (oral exam) takes place. PhDs in many other European countries and certain commonwealth countries such as Australia, take a similar length of time. For other countries such as the US it will typically be a year or two longer than this, which could be a positive or negative depending on why you’re doing a PhD!
If you’re considering applying for a PhD, here are some relevant posts for you which may be useful:
- How to apply for a PhD
- PhD FAQs – A Complete Beginner’s Guide to Doctoral Study
- How much work is a PhD?
Putting a PhD in career context
Still on the fence as to whether you really want to spend roughly four years of your life on a PhD?
Let’s put it in perspective.
If you come out of uni at age 22 and retire at age 68, you’ll have a career of approximately 46 years:
Let’s say after a few years of working you decide to do a PhD. We’ll assume in total it takes 4.5 years – about the maximum length of time a full-time PhD can be from start to end in the UK.
Now let’s slot in that PhD in orange:
This shows the average PhD-holder still has about a 40 year career ahead of them if they were to work until state pension age in the UK! So doing a PhD lowers your career by 4-4.5 years, or as a percentage: less than 10%!
In reality, retirement age is very likely to be pushed well into the 70s by that time, making the time spent on a PhD even less of an issue. Sidenote: while you’re young take the opportunity to build up financial freedom!
Is a PhD worth it? I’ve delved into this more here, but it will depend a bit on your own circumstances so I can’t definitively answer that for you. But it’s important to recognise that doing a PhD isn’t taking much time away from your career and could potentially add a lot to it!
Read on for details on why a PhD takes around four years to complete.
The structure of a PhD
There are four parts to getting a PhD:
- The main one: working on your project and doing the research!
- Writing up your work and submitting it as a thesis (or papers if your university allows it)
- The oral examination (viva)
- Making any corrections to the thesis requested by the examiners and submitting the final version to the university
Let’s quickly cover each one of these parts in a little more detail:
1. PhD project: Carrying out research
This section is the core of your PhD and the bit where you actually do some research. Some people may divide the PhD project into sections such as:
- Reading literature
- Deciding on a research project direction
- Trying out different experimental methods
- Main experiments & data collection
- Analysis
Every project (and person) is so different that it would be useless to give you a generic timeline with how long each section could take. Points 2 and 3 may even appear in different orders depending on your project. There is no convention! In addition, rarely will someone carry these tasks out in series with no overlap between them. Working on tasks in parallel helps to keep your days more varied and interesting too.
If you’ve already got a very well defined project you may whiz through the first three points. The same goes for if you’re taking over from a previous student who has already got your project going. For my project I was pretty much starting from scratch in a lot of regards. I also had a scholarship with a lot of freedom, so spent more time on these preliminary stages. It really varies a lot, so let’s just cover how long the research typically lasts in total:
PhD research duration
Two main factors will typically dictate how long is spent on research before writing up:
- Funding: The majority of PhD students in STEM are funded (post on how here, and how much here) and no one wants to be supporting themselves once the money runs out. Therefore usually PhD students will aim to complete all research (and ideally writing up) by the time their funding ceases. Most PhD projects in the UK are funded for 3 – 3.5 years. The maximum is four years, for reasons you’ll see in a moment. Personally my scholarship was for 3 years and then I was separately employed for another five months by my supervisor.
- Submission deadline: You can imagine that the completion rate of PhDs isn’t great once funding ceases. You’re seeking employment to support yourself and suddenly the PhD isn’t a focus. More and more universities are now imposing strict deadlines for submission to boost the chances of students successfully completing the degree. This deadline to submit your thesis is often four years from your start date.
A student will typically work back from these deadlines, estimating how long is required for writing up and spend all of the remaining time doing research.
Approximate research duration: Overall, from induction through to finishing data analysis will typically take 2.5 – 3.5 years.
2. Writing up
As we covered above, there are two main factors which will usually control how much time is available for the project as a whole. It is up to the student to decide how late they leave it to finish conducting research and start writing up.
For some people writing up can take a significant number of months. This may be particularly true for non-native speakers.
My somewhat controversial suggestion is to leave it as late as possible to go into the full-time writing-up stage. This allows you to maximise the amount of time you’re able to access labs or any specialist resources which will disappear once you leave. It’s also very easy to procrastinate whilst writing, therefore by constraining the timeline you’re less likely to waste your time.
However not officially being in the ‘writing-up’ stage, doesn’t mean doing no writing at all in advance. In fact let’s answer a few common questions related to writing up:
Can you write up as you go along?
Yes! You can of course write whenever you fancy it, but additionally typically there will be a few assessment checkpoints during the research phase of your project. For the first of them, which occurs around 9 months after starting the project, you’ll usually have to produce a report. This often includes the rationale for the project, a literature review and your progress so far. At Imperial it was called the Early Stage Assessment (ESA) and others know it as the upgrade interview.
Even if you do no other writing up during your project, this report can still form a useful starting point for your thesis. My report was just under 20 pages long and the literature review component formed the foundations for the literature review in my PhD thesis.
There is often a second checkmark at 18-24 months (called the “Late stage assessment” or “LSR” at Imperial). This may again may include a formal report which could go some way towards your thesis. The alternative to writing a report for the LSR is showing a paper you’ve submitted to a journal: a handy reason to write papers, which we’ll come onto more in a second.
You can take it further and write up chapters of your work as you go if you want. The most obvious reason for doing so it to produce papers of each results chapter which we’ll now discuss.
What about papers?
I strongly recommend PhD students submit papers during their PhD. I only had one published by the time of my viva and that single paper was immensely valuable in providing evidence that I’d done novel research of a high enough standard. See my guide to writing your first paper here:
If nothing else, writing up your work as papers serves as a useful way to split your PhD work into sections which can then become chapters of a thesis.
Some universities may allow you to submit a string of papers instead of a thesis. I know that this is common in other parts of Europe.
By the time I submitted my thesis I had one results chapter accepted as a paper, another two papers roughly drafted and another chapter I hadn’t really worked on. At Imperial you do have to submit a thesis, but crucially the content can include submissions for papers. I had to do a bit of work converting papers into chapters but it was minimal, maybe a few days work.
Your mileage may vary: I know that some other universities don’t allow you to copy text (or figures) word for word from papers due to plagiarism, which of course suddenly creates a lot of extra work. Either way, writing up your research as papers during a PhD is strongly encouraged if you can!
Should you care about having a ‘nice looking’ thesis?
This is a question only you can answer. If you want a thesis formatted wonderfully in LaTex with stunning figures etc you’ll of course have to dedicate additional time to writing the thesis.
For me I didn’t (and don’t) care at all about having a nice looking thesis. I’d much rather invest energy in writing things people will actually read: papers.
Do remember that what you submit to the examiners is merely a draft and isn’t your last chance to make changes!
Approximate duration for writing up: Typically 2 – 6 months, but it doesn’t have to take this long!
3. Scheduling and passing the oral examination (viva)
When you’re coming to the end of your PhD you’ll discuss potential examiners with your supervisor and begin organising potential dates for your exam: known as a viva here in the UK. In the UK you’ll usually have a minimum of one external examiner (from another university) and one internal examiner (from your university).
The date will usually be a minimum of two months after you submit your thesis. You can potentially get away with a bit shorter, but universities don’t like doing it in case of any holdups. It’ll ultimately come down to finding a suitable time which works for your examiners.
I know of people who’ve had to wait a lot longer than a few months because of difficulties finding a time which works for all the examiners, especially if substantial travel is required. One of the perks of the current C-19 working from home arrangement is that examinations may be more easily scheduled.
The oral exam itself is only one day. I’m putting together a separate post to cover what the viva experience is like.
Approximate duration for scheduling and passing the exam: Typically three months.
4. Making any corrections to the thesis
The examination will in part focus on the quality of your written thesis. Some people pass the viva with no corrections. Therefore you could simply use the copy you sent to the examiners as your final copy of the thesis, requiring no further work.
However it is rare to pass with no corrections and instead it is likely that there will be “minor corrections” suggested to improve the thesis. These corrections may be to:
- Improve clarity
- Add some further necessary detail, including potential additional analysis
- Removing unsubstantiated claims
- Correcting typos and grammatical errors
It is also possible for “major corrections” to be requested, requiring much more substantial work – usually including further experiments.
In the case of minor corrections, sometimes the examiners will want to see the updated thesis, other times they’re happy to let your supervisor approve the changes.
Typically in the UK you are given a deadline to submit these corrections within three months of your viva. Of course it usually doesn’t actually take anywhere near three months of solid work to make the changes, but the examiners and university recognise that by then you’ll have ceased being a PhD student and likely have other commitments. Plus, not everyone wants to dive straight back in after the viva!
Approximate duration for making changes to your thesis: 0 – 3 months.
5. Awaiting confirmation of your PhD
Once you’ve submitted your final copy of the thesis you’ll have to wait for the registry team to formally confirm your PhD. At Imperial this is done once per month. And you’ll get an email something like this:
Duration: one month or less.
So how long does it take to get a PhD in total?
Now we’ve covered all the separate stages of a PhD, hopefully you have a better sense of how long it could take to get a PhD.
UK average
Wondering how long is a PhD in the UK? In the UK the average time from starting the PhD to submitting the thesis is approximately three and a half years. It’ll then take another 4-6 months until the viva has been completed, the final thesis copy submitted and for the university to award the PhD. This brings us to a total length of approximately 4 to 4.5 years for a PhD in the UK.
This assumes that study towards the PhD is full-time. Of course if you’re working part-time on the project the duration can increase considerably.
If the PhD is as part of a CDT/DTC programme the timeline may be slightly different, but won’t necessary be much longer. In a CDT you’ll usually spend a year studying for an MSc, followed by three years working towards the PhD, at which point you’ll submit the thesis. Therefore the total time for a PhD as part of a CDT with a MSc+PhD programme may still be just over four years, including the MSc.
My experience
I finished my PhD earlier this year and this is how long each of the PhD stages took me:
| Section | Start | End | Duration |
|---|---|---|---|
| 1. Doing the research | 1st October 2016 | 23rd January 2020 | Three years & four months |
| 2. Writing thesis | 24th January 2020 | 14th February 2020 – Thesis Submission* | Three weeks** |
| 3. Viva | 25th March – Viva passed with minor corrections | Six weeks after thesis submission | |
| 4. Minor thesis corrections | 26th March | 30th March – Final thesis submitted*** | Four days |
| 5. Confirmation of the PhD | 1st April | Two days | |
| TOTAL | 1st October 2016 | 1st April 2020 | 3 years, 7 months |
* I wanted to arrange a holiday for April (which didn’t happen) so knew when I wanted to have the viva and worked back from there. I could have submitted the thesis 7.5 months later and still have been within the four year deadline, but wasn’t interested in stringing it out!
We arranged the viva back in January and submitting the thesis six weeks before the viva was about the minimum reasonable period. You may be required to submit the thesis before officially scheduling the viva.
** I’m a fast writer and didn’t massively care about the quality of the thesis but even so, couldn’t write a whole thesis in three weeks! Crucially I had most of the results chapters already written by this point.
I spent about a week writing the literature review section, a week on the introduction and discussion chapters and a week putting it together. Once you have your results sections don’t spend ages faffing with the other sections (intro, lit review, discussion), they’ll swallow up as much time as you give them.
*** Had I been able to go away on my two month holiday I’d have left the thesis corrections for when I got back. But since I wasn’t able to go, I decided to crack on with them right away. Most people would tend to have more of a break before submitting the corrected version, but I knew that if I submitted quickly then I’d be in time for the PhD to be confirmed in April – just a few days later. There is also something funny about having a PhD confirmed on April Fools’ Day!
How long does it take to get a PhD outside of the UK?
PhD programmes vary in structure and length around the world. PhDs in mainland Europe and Australia are typically of similar length to the UK. Though if you’re looking to study for a PhD in the US you can often expect to be studying for an extra year or two.
In the US PhDs typically begin with formal courses and lab rotations , with PhD projects not being decided until midway through your second year. This is a similar parallel to undergraduate degrees being less specialised than in Europe. Therefore in the US PhDs typically take 4-6 years to complete.
More details for PhDs around the globe can be found on this handy set of pages FindAPhD has put together.
Hopefully you’re now able to answer how long it takes to get a PhD. If you have any other PhD-related questions you’d like answered please let me know and I’ll be happy to address them!
Footnotes for the lifetime graphic:
* UK life expectancy for a current 20 year old is estimated to be around 87 years.
* The figure was inspired by some of the amazing posts on Wait but Why. If you’ve not already checked out the website, please do!
