1. Why "I know X words" is meaningless
If you ask someone how many words they know and they say 8000, that number conflates two very different things:
- Passive vocabulary — what you recognise when reading or listening
- Active vocabulary — what you can produce when writing or speaking
Active typically runs at ~40% of passive. So "8000 words" usually means about 3200 truly usable.
2. Approximate vocab-size by CEFR level
| CEFR | Passive | Active |
|---|---|---|
| A1 | 600–800 | 250–350 |
| A2 | 1200–1600 | 500–700 |
| B1 | 2500–3000 | 1200–1500 |
| B2 | 5000–6000 | 2500–3000 |
| C1 | 8000–10000 | 4500–5500 |
| C2 | 12000+ | 7000+ |
Numbers are mid-range estimates from corpus research; specific tests may diverge.
3. Three free tests you can take today
Test 1 — testyourvocab.com
About 10 minutes, you check off words you recognise. Returns a passive vocabulary estimate. Best for first-time baseline.
Typical results:
- Native speaker (adult): ~28,000
- B2 non-native: ~6,000
- C1 non-native: ~8,000
Test 2 — Lexile reading assessment
Reads a passage, asks comprehension questions, outputs a Lexile score (700L–1300L+) mapped to your reading level. Best for "what difficulty of material can I actually understand?"
Approximate CEFR map:
- 700–900L ≈ B1
- 1000–1100L ≈ B2
- 1200–1300L ≈ C1
Test 3 — TTR (Type-Token Ratio) on your own writing
Open our writing tool, write a 250-word Task 2 essay, and check the TTR statistic:
| TTR | Diagnosis |
|---|---|
| < 45% | Vocabulary repetition; active range tight |
| 45–55% | Normal B2 |
| 55–65% | C1 territory |
| > 65% | Near-native / C2 |
This is the simplest way to check whether your active vocabulary is sufficient.
4. Vocabulary requirements per exam (rough thresholds)
| Exam + target | Passive | Active |
|---|---|---|
| IELTS 6.0 | ~5000 | ~2500 |
| IELTS 6.5 | ~5500 | ~2800 |
| IELTS 7.0 | ~7000 | ~3500 |
| PTE 65 | ~6000 | ~3000 |
| LanguageCert B2 | ~5500 | ~2800 |
| LanguageCert C1 | ~8500 | ~4500 |
| Password 6.0 | ~5500 | ~2800 |
| DET 120 | ~5500 | ~2800 |
| DET 140 | ~7000 | ~3500 |
Note: target 6.5 on most tests corresponds to about 5500 passive — which is exactly what our L2 vocabulary list is built around.
5. Three stages of vocabulary growth
Stage 1 — Foundation (A2 → B1)
- Focus: top 2000 high-frequency words
- Method: word + sentence + meaning
- Tools: L1 vocabulary + dictation
Stage 2 — Expansion (B1 → B2)
- Focus: academic + journalistic words 2000–5000
- Method: word + collocation + context
- Tools: L2 vocabulary + BBC Learning English reading
Stage 3 — Refinement (B2 → C1)
- Focus: precise collocations + synonym distinctions, 5000–8500
- Method: word + 2–3 collocations + one negative example
- Tools: L3 vocabulary + Economist + writing self-rubric
6. Why "wordlist cramming" is inefficient
Imagine cramming 50 new words a day. After a month:
- True retention: ~60% = 900
- Usable in writing: ~30% = 450
- Usable in speaking: ~15% = 225
Now imagine 50 new collocations a day. After a month:
- True retention: ~80% = 1200
- Writing-usable: ~60% = 900
- Speaking-usable: ~40% = 600
Two to three times as effective. Treat collocations as the unit of vocabulary growth, not single words.
7. Action steps this week
- Take testyourvocab.com — baseline passive
- Write a 250-word essay; check TTR — current active
- Use the table in §4 to identify how far you are from your target
- Choose L1, L2 or L3 vocabulary to match
- Re-test TTR weekly to watch active vocabulary rise
Vocabulary is not about quantity — it's about active-passive balance. A new usable collocation is worth ten new words you only recognise.
Frequently asked questions
How many words do I need to know for IELTS Band 6?
About 5,000–6,000 active words, supported by ~10,000 passive recognition. Note that 'knowing' a word means recognising it AND being able to use it in context — passive recognition alone is insufficient.
What's the difference between active and passive vocabulary?
Active vocabulary is what you can produce in speaking and writing. Passive vocabulary is what you can recognise when reading or listening. Passive is typically 2–3× larger than active for any learner.
How do I test my own vocabulary size?
Use free tests like Test-Your-Vocab.com (recognition) and combine with a writing self-rubric for active vocabulary. Take 2–3 different tests and average — single-test results vary widely.
Does memorising word lists work?
Poorly. Word lists build recognition but not usage. Better: encounter words in real sentences, drill via SRS with example sentences, and force usage in your own writing within a week of first encounter.