What is a vocabulary size test?
A vocabulary size test estimates how many words you know in a language by checking which words you recognise across a range of difficulty — from the most common everyday words to rare, advanced ones. Instead of asking you to define every word, it samples words at different frequency levels and scales up from how many you know.
The test above mixes real words with a few made-up ones. Marking a made-up word as "known" reveals over-confidence, so your final number is corrected for guessing — the same technique (a "Yes/No" recognition test) used in vocabulary research.
How many words do I need to know?
As a rough guide, an educated native speaker knows around 15,000–20,000 word families. You need far fewer to function: about 3,000 of the most frequent words cover the large majority of everyday speech. Here is roughly how a known-word count maps to CEFR level:
| Words known | Approx. CEFR | What that means |
|---|---|---|
| Under 750 | A1 | Basic phrases, greetings, everyday objects |
| 750–1,500 | A2 | Simple conversations, routine daily topics |
| 1,500–3,000 | B1 | Independent use — travel, opinions, familiar topics |
| 3,000–5,000 | B2 | Comfortable across most topics; news and work |
| 5,000–9,000 | C1 | Advanced — nuance, implicit meaning, professional use |
| 9,000+ | C2 | Near-native range |
How does this vocabulary test work?
The test shows words sampled from several frequency bands — the most common 1,000 words, the next 1,000, and so on out to the rarest. For each band it measures the share you recognise, then multiplies by how many words that band represents in the language and adds the bands together. That gives an estimate of your total vocabulary.
Because tapping every word would inflate the score, the made-up words act as a check: the more of them you claim to know, the more your estimate is discounted. The result is shown as a word count and an approximate CEFR range, not a precise certification.
What can I do with my vocabulary size?
Your word count is a fast snapshot, but vocabulary is only one skill. To see your full level across reading, listening, grammar and more, take the free 5-minute CEFR test — it places you in a CEFR range the same way exams like DELE and Cambridge report results.
If you want to grow the number, the most efficient path is to learn words in frequency order and review them so they stick. Nivelo's spaced-repetition flashcards, graded reading and practice are built to do exactly that — turning your vocabulary estimate into a plan.