How the IELTS band descriptors actually work
Most people study for a number. Examiners never think in one — they think in four descriptors, and your band is the honest average of them. Once you can see the page the examiner sees, your practice stops being guesswork.
You are scored on four things, not one
Writing and Speaking are each marked against four equally-weighted criteria. There is no single “writing score” hiding in the examiner’s head — there are four sub-scores, and they average to the band you see. Reading and Listening are different: they are objectively marked out of 40 and converted to a band, so this article is about the two productive papers, where a human decides.
| Writing | Speaking | What it measures |
|---|---|---|
| Task Response | Fluency & Coherence | Do you fully answer, develop ideas, and keep going without stalling? |
| Coherence & Cohesion | — | Are ideas ordered into clear paragraphs and linked so the reader never gets lost? |
| Lexical Resource | Lexical Resource | Is your vocabulary wide, precise and natural — not just “big words”? |
| Grammatical Range & Accuracy | Grammatical Range & Accuracy | Do you use varied structures, and are they correct? |
| — | Pronunciation | (Speaking only) Can you be understood easily, with natural stress and rhythm? |
Each criterion is worth 25% — so your weakest one sets the ceiling
Because the four are averaged, they behave like the slowest runner on a relay team. A band 8 in three criteria and a band 5 in one lands you near 6.5, not 7.5. This is why “I just need better vocabulary” usually backfires: pouring effort into your strongest criterion moves the average far less than fixing your weakest.
The practical rule: find your lowest descriptor and spend your hours there. A candidate stuck at 6.5 almost always has one criterion dragging — most often Coherence & Cohesion in Writing, or Grammatical Range in Speaking.
How a band is actually decided: best fit, not a checklist
Examiners do not tick boxes and add points. For each criterion they read the band descriptor — a paragraph of prose per band from 0 to 9 — and choose the one your performance best fits, even if a detail or two belongs to the band above or below. Your job is not to be flawless; it is to sit clearly inside the descriptor for your target band on all four counts.
That reframes preparation. Instead of asking “was that good?”, ask “which band does this paragraph best fit, and what is the one sentence in the next band up that mine is missing?” That question is answerable. “Was it good?” is not.
Where half-bands come from
Your overall band is the average of the four papers — Listening, Reading, Writing and Speaking — rounded by an official rule: an average ending in .25 rounds up to the next half band, and .75 rounds up to the next whole band. So 6.5, 6.5, 6.0, 7.0 averages to 6.5; but 6.5, 7.0, 6.5, 7.0 averages to 6.75 and rounds up to 7.0.
What this means for your week
- Score a real answer against all four descriptors — not one overall gut feeling. Name a band for each criterion.
- Pick the lowest. That is your project for the next two weeks; the others tick over on maintenance.
- For that criterion, read the descriptor one band above yours and write down the single concrete thing it asks for that you are not yet doing.
- Drill that one thing until a fresh answer sits clearly in the higher band, then re-score all four and repeat.
This is exactly the loop Axiom automates: every Speaking and Writing answer comes back scored on each descriptor, with the specific fix that moves the lowest one — so you always know which quarter of your band you are working on.