OET Writing guide
OET Writing score explained: what grade B and 350 mean
Your OET results show a number from 0 to 500 and a letter grade for each sub-test. Regulators usually ask for a grade B (350) or a C+ (300), and Writing is the sub-test that holds most candidates back. This guide explains the scale, how a Writing score is built from six criteria, and what a letter at grade B typically does.
This is an independent summary of public information. LetterScore AI is not affiliated with OET or Cambridge Boxhill Language Assessment. Check the official OET website for current scoring information, and your regulator for the grade you need. Any score from LetterScore AI is a practice estimate, not an official result.
The OET score scale
Each of the four sub-tests (Listening, Reading, Writing and Speaking) is reported separately, on a scale from 0 to 500 in steps of 10. Each score falls into a letter grade from A (highest) to E (lowest). Regulators set their requirements per sub-test, so a strong Listening score cannot make up for a weak Writing score.
| Grade | Score range | What it broadly means (our summary of OET's descriptors) |
|---|---|---|
| A | 450–500 | Very fluent, effective communication with patients and colleagues, with fully appropriate register and vocabulary |
| B | 350–440 | Effective communication with appropriate register and vocabulary; only occasional inaccuracies |
| C+ | 300–340 | Can keep communication going in a healthcare setting despite occasional errors and lapses |
| C | 200–290 | As C+, at a lower level |
| D | 100–190 | Some interaction on straightforward matters; frequent errors strain communication |
| E | 0–90 | Manages short, simple messages with help; errors cause breakdowns |
So "grade B" and "350" are often used interchangeably, but strictly B is a range: 350 is the lowest score that counts as B. A requirement of "B" means at least 350. A requirement of "C+" means at least 300.
Some regulators now state numbers rather than grades. Australia's boards, for example, ask for 350 in Writing but 360 in Reading and Speaking for tests taken on or after 23 April 2026, so a 350 in Reading would be grade B but would not meet that rule. Read your regulator's wording carefully. See OET requirements by country for the current figures.
How OET Writing is scored
Your letter is assessed against six criteria. Purpose is scored out of 3; the other five are each scored out of 7.
| Criterion | Maximum | The question it asks |
|---|---|---|
| Purpose | 3 | Can the reader see quickly and precisely what you want them to do? |
| Content | 7 | Is the information this reader needs included and accurate? |
| Conciseness & Clarity | 7 | Is irrelevant information left out and the case summarised efficiently? |
| Genre & Style | 7 | Are register, tone and medical language right for this reader? |
| Organisation & Layout | 7 | Is the letter logically ordered, with key information easy to find? |
| Language | 7 | Are grammar, vocabulary, spelling and punctuation accurate enough not to get in the way? |
That gives a maximum raw total of 38. The criterion scores are combined and converted to the 0–500 scale. OET does not publish the exact conversion, so you cannot calculate your official score from criterion marks yourself.
What OET does say publicly is the anchor for grade B: a letter at grade B typically scores 2 out of 3 for Purpose and 5 out of 7 for each of the other five criteria. That is the most useful target for practice. Our guide to the OET Writing criteria explains what each level looks like.
What the B anchor means in practice
- Purpose 2/3: the reader can find why you are writing and what you want, even if it is not as prominent or as fully developed as it could be. A 3 states the purpose clearly at the start and expands it with specific requests later.
- 5/7 on the others: the letter mostly covers what the reader needs, mostly leaves out what they do not, uses mostly appropriate tone and organisation, and has only minor language slips that do not affect meaning.
Notice the word "mostly". A grade B letter does not need to be perfect. It needs to be consistently good across all six criteria, without one weak area dragging it down.
Why Writing is often the hardest sub-test
Many candidates reach B in Listening, Reading and Speaking before Writing. A few reasons are common:
- It tests decisions, not just English. Case notes include details the reader does not need. Content and Conciseness & Clarity reward choosing well, and many candidates copy too much "just in case".
- Time pressure. You have 5 minutes to read and 40 minutes to plan, write and check one letter. Errors in names, doses and tenses creep in when the checking time disappears.
- The reader changes every time. A letter to a GP, a community nurse and a patient's parent each need a different level of medical language. Genre & Style reflects whether you adjusted.
- Feedback is harder to get. Listening and Reading have right or wrong answers you can check yourself. A letter needs someone, or something, to judge it against the criteria.
- Language errors cost twice. Errors are marked under Language, but unclear sentences can also lower Conciseness & Clarity.
What a grade B letter typically looks like
Based on the public criteria, letters at or above the B line tend to share these features:
| Part of the letter | What a B letter usually does |
|---|---|
| Opening | States the purpose and the action wanted in the first one or two sentences, for example "I am writing to refer Mrs Tan for assessment of her worsening exertional breathlessness." |
| Body | Includes what this reader must act on: current problem, relevant history, medications, risks, what has been done. Leaves out details that do not affect care. |
| Summary | Turns lists of observations into trends ("her blood pressure has remained above target despite two dose increases"). |
| Order | Follows the reader's priorities rather than the order of the case notes, one topic per paragraph. |
| Tone | Professional, no contractions, medical terms suited to the reader and explained for a lay reader. |
| Close | Ends with specific requests or follow-up, not just a general thank you. |
| Accuracy | Names, numbers and doses match the notes; tenses follow the timeline; only minor slips. |
If you are currently at C+, our guide to moving from C+ to grade B gives a weekly practice routine and a self-check list. The 12 common OET Writing mistakes and the OET letter format template cover the most frequent ways letters lose marks.
Using practice scores sensibly
Teachers, study partners and tools like LetterScore AI can estimate your criterion scores, but only OET assessors give official results. Treat practice scores as a guide to your weakest criterion, not a prediction of your final number. If your estimates show Purpose and Content at B level but Language below it, that tells you where to spend the next two weeks.
Frequently asked questions
Is 350 a grade B in OET?
Yes. Grade B covers scores from 350 to 440, so 350 is the lowest score that counts as B. A score of 340 is C+, which covers 300 to 340.
How many marks do I need in each criterion to get a B in OET Writing?
OET says a grade B letter typically scores 2 out of 3 for Purpose and 5 out of 7 for each of the other five criteria. The exact conversion from criterion scores to the 0–500 scale is not published.
Do I need a B in Writing or is C+ enough?
It depends on your regulator and profession. As checked in October 2026, UK, Irish and New Zealand nursing regulators ask for C+ (300) in Writing, while the GMC and the Irish Medical Council ask for B, and Australia's boards require 350 for tests taken on or after 23 April 2026. Always confirm with your regulator.
Can LetterScore AI give me my official OET score?
No. LetterScore AI is an independent practice tool. It gives estimated scores for the six criteria with evidence from your letter, but only OET issues official results.