It is the question every student asks their supervisor, and the answer is almost always some version of “as long as it needs to be” — which is true, and completely useless when you are staring at a word count.
So here is a more practical answer to how long should a literature review be, along with the reasoning behind it, so you can work out the right length for your own project rather than borrowing someone else’s number.
The short answer
For most dissertations and theses, the literature review runs to roughly 20–30% of the total word count.
That gives you:
- 8,000-word dissertation — around 1,600 to 2,400 words
- 10,000-word dissertation — around 2,000 to 3,000 words
- 15,000-word masters dissertation — around 3,000 to 4,500 words
- 80,000-word PhD thesis — often a full chapter of 12,000 to 20,000 words, sometimes split across two
A standalone literature review essay, set as its own assignment, is different again. Those are usually 1,500 to 3,000 words and the brief will normally tell you.
Now the important caveat: your handbook overrides all of this. If your department specifies a chapter breakdown, follow it precisely. Some courses want 40%. Some want 15%. Neither is wrong at that institution.
How many pages is that?
Word counts are what get marked, but plenty of students think in pages, and some briefs are still set that way.
Assume around 250 words per page double spaced in 12-point Times New Roman or Arial, which is what most universities ask for. Single spaced, it is roughly 500. On that basis:
- 2,000 words — about 8 pages double spaced
- 3,000 words — about 12 pages
- 4,500 words — about 18 pages
- 12,000 words — about 48 pages, which is why doctoral reviews are usually split into sections
Two things distort this. Long block quotations and tables eat vertical space without adding many words, so a page estimate can run ahead of the word count. Your reference list does not count towards the review at all, and it can easily add several pages of its own.
If your brief is given in pages, convert it to words before you start planning. Nobody drafts to a page target successfully.
Why the percentage varies so much
The length of your review is really a function of what your project needs, not a fixed proportion.
You will need a longer review if your topic sits across two or more fields, if there is a long history of research you need to trace, if you are arguing that existing work is flawed, or if your study is theoretical rather than empirical. Theory-heavy projects sometimes run to 40% or more, because the review is much of the contribution.
You can get away with a shorter one if your topic is narrow and recent, if your project is mostly practical or design-based, or if the field genuinely is small. Some emerging topics have thirty relevant papers in total, and padding a review to hit a percentage is worse than writing a tight one.
How long should a literature review be in a research proposal?
Much shorter than students expect, and this catches people out because they apply dissertation proportions to a document that is doing a completely different job.
In a proposal, the review is usually 500 to 1,500 words, or one to two pages inside a proposal of 2,000 to 3,000. For a doctoral application it may stretch to 2,000, but rarely beyond.
The reason is purpose. A dissertation review demonstrates command of the field. A proposal review only has to convince a committee of three things: that you know the territory, that there is a genuine gap, and that you are the person who has read enough to fill it. You are proving competence, not exhausting the subject.
In practice that means naming the two or three debates that matter, citing the handful of works that define them, and getting to your gap quickly. Save the detailed evaluation for the dissertation itself. Reviewers reading twenty proposals in an afternoon will thank you for it.
There is more on getting the rest of that document right in our guide to writing a research proposal your supervisor will approve.
How long does a literature review take to write?
Length is one question. Time is the one that actually determines whether you make your deadline, and the honest answer is that it takes longer than almost anyone plans for.
For a masters review of around 3,000 words, working alongside other commitments, budget six to eight weeks. That breaks down roughly as:
- Searching and sifting — one to two weeks. Finding the literature is fast. Deciding what is actually relevant is not.
- Reading and note-taking — two to three weeks. Reckon on thirty to forty-five minutes per paper if you are reading properly and taking notes you can use later.
- Organising into themes — a few days, and the step most people skip. It is also the step that decides your mark.
- Drafting — one to two weeks.
- Revising — one week, minimum, and expect at least one structural rewrite.
An undergraduate review of 2,000 words might take four weeks. A doctoral review is measured in months, and it is normal to keep revising it until the thesis is submitted, because the field moves while you are working.
The part that consistently overruns is reading. If you have forty sources and give each one forty minutes, that is close to thirty hours before you have written a sentence. Plan for it rather than discovering it.
How many sources is enough?
Rough guidance, and it is only rough:
- Undergraduate dissertation — 25 to 40 sources
- Masters dissertation — 40 to 70
- PhD thesis — well over 100, often several hundred
Do not treat these as targets to hit. A review citing thirty papers that genuinely shaped your thinking reads far better than one citing eighty, sixty of which appear once in a list and never again.
Markers can tell the difference immediately. A source you have actually read gets discussed, compared or challenged. A source you have padded with gets a single passing mention.
The real problem is usually structure, not length
When a supervisor says a review is too long, they often mean it is repetitive. When they say it is too short, they usually mean it is shallow. In both cases the word count is a symptom.
The most common structural failure is what markers sometimes call the annotated bibliography problem: paragraph after paragraph that goes “Smith (2019) found X. Jones (2020) found Y. Patel (2021) found Z.” Each one summarised in turn, none of them connected.
That structure eats words at an alarming rate and says almost nothing. It also caps your mark, because summarising is a lower-order skill than synthesising.
The fix is to organise by theme or debate, not by author. Instead of a paragraph per study, write a paragraph per idea, and bring several studies into it:
“Research on this question splits along methodological lines. Studies using self-report measures consistently find a strong association (Smith, 2019; Patel, 2021), while those using observational data report a much weaker effect (Jones, 2020). This divergence suggests the relationship may be partly an artefact of how it is measured.”
Three sources, one paragraph, and an actual argument. The author-by-author version would have taken three paragraphs to say less.
If it is easier to see the difference side by side, we have a worked literature review example that takes the same five sources and writes them out both ways.
If that is the part you are stuck on, we have a longer guide on how to structure a literature review that works through the main organising patterns in detail.
What has to be in there
However long yours ends up, a review is expected to do four things:
- Map the field. What is already known, and who established it.
- Group and compare. Where scholars agree, where they disagree, and why.
- Evaluate. Which studies are convincing, which have methodological problems, and how you know.
- Identify the gap. What has not been settled — and this gap must be the thing your study addresses.
That last point is the one students most often miss. Your review is not a neutral survey. It is the argument for why your research needed doing. If a reader finishes it without understanding why your study exists, it has not done its job, no matter how many sources it cites.
Trimming a review that has run long
If you are over, cut in this order:
Background that belongs in the introduction. General scene-setting about why the topic matters usually is not review material.
Studies that agree with each other. If five papers found the same thing, cite all five in one bracket and discuss one in detail. You have lost nothing.
Method descriptions. You rarely need to explain how a study you are citing was conducted, unless the method is the point you are making about it.
Long quotations. Paraphrase and cite. A quotation should earn its place because the exact wording matters, not because it fills space.
Definitions of common terms. Your marker knows what your field’s basic vocabulary means.
Padding a review that is too short
If you are genuinely under length, resist the urge to add more summaries. Add depth instead.
Go back to the studies you have already cited and evaluate them properly — sample sizes, contexts, limitations, whether the findings transfer to your setting. Look for the counter-argument you have not represented. Widen slightly into an adjacent field and explain the connection. Trace how thinking on your question has changed over time.
All of that adds words while also adding marks. More summaries add words and nothing else.
It is also worth reading through the mistakes that cost marks in literature reviews before you start adding anything, because a short review is often short for a reason that more words will not fix.
One last check before you submit
Read your review and ask whether someone unfamiliar with your topic would finish it able to say, in one sentence, what your study is going to do and why nobody has done it yet.
If yes, the length is right, whatever the number says. If no, more words will not fix it.
Common questions about literature review length
How long should a literature review be for a 10,000 word dissertation?
Around 2,000 to 3,000 words, which is the usual 20 to 30 per cent band. Take the lower end if your study is empirical and your fieldwork chapters need the room, and the higher end if your argument depends on establishing where the existing research falls short.
How many pages should a literature review be?
At roughly 250 words to a double spaced page, a typical masters review of 3,000 words comes to about twelve pages. Convert any page target into words before planning, because tables and block quotations distort the page count badly.
Can a literature review be too long?
Yes, and it is penalised more often than students realise. An overlong review usually signals that you have summarised rather than synthesised, or that you have included material to show effort rather than because it bears on your question. Going more than about ten per cent over a stated limit also risks a straightforward mark deduction at many universities.
Does the reference list count towards the word limit?
Almost never, but confirm it in your handbook rather than assuming. Appendices are usually excluded too. In-text citations normally do count, which matters more than it sounds when you have several hundred of them.
How long does a lit review take to write?
Six to eight weeks for a masters review of 3,000 words, alongside other work. Reading is the stage that overruns, not writing. Forty sources at forty minutes each is close to thirty hours before you draft a word.
Is a systematic review the same length?
No. Systematic reviews follow a defined protocol and report their search strategy, inclusion criteria and screening numbers, all of which adds words. They commonly run half as long again as a traditional narrative review covering the same ground, and often longer.
If you are stuck
Literature reviews are the chapter students most often rewrite two or three times, usually because the structure was wrong rather than the reading. Reorganising round themes rather than authors solves most of it.
If you would rather have help, our dissertation writing help covers literature reviews specifically, and we work on thesis writing at masters and doctoral level too. There is a related guide on structuring your methodology chapter, which is usually the next thing you will be writing.