How many words does a C2 speaker know?

About 7,000 to 9,000 word families, roughly 11,000 to 18,000 individual words. That's enough for precise, flexible use across demanding work, study, and social situations.

On vocabulary tests that sample the 5,000 most common dictionary words, C2 learners score about 4,500 to 5,000. Every published number is real; they just count different things. That's why one article says 5,000 and another says 16,000.

Why every source gives a different number

The Common European Framework of Reference (CEFR) itself publishes no official word counts for any level, A1 through C2. Every number you'll find comes from vocabulary research, and the spread comes from the unit, not the research. Some studies count word families, some count lemmas (a dictionary headword plus its inflections), and some count every individual word. One family is roughly 1.6 to 2 individual words, so the same vocabulary produces very different totals depending on how you count.

The main measurements behind the numbers you'll see:

4,500 to 5,000 is Milton and Alexiou's measured band for C2 learners on the X_Lex test, which samples the 5,000 most common lemmas. It's a score out of 5,000, not a total vocabulary size.

7,000 to 9,000 word families is Paul Nation's suggested C2 range in his CEFR mapping. It reflects the vocabulary needed for near-native comprehension of most texts. Nation's C1 band is 5,000 to 6,000 families, so C2 adds roughly 2,000 to 3,000 more, mostly low-frequency, academic, and idiomatic vocabulary.

16,000+ words is the popular doubling-table figure for C2. It is an internet extrapolation, not a figure in the research. The table simply doubles its total at every CEFR level, and usually leaves the unit unclear.

Two caveats. These are receptive counts from English-language studies: passive vocabulary you recognize when reading or listening. The vocabulary you can actively use in speech is smaller. And educated native speakers carry well past 15,000 word families, so even C2 is not native-sized. C2 means expert, flexible use, not possession of every word a native speaker knows.

Is C2 vocabulary the same as native?

No. A C2 learner may know 7,000 to 9,000 word families, while educated native speakers carry well past 15,000. C2 is expert use: choosing precise words, following shades of meaning, and handling unfamiliar language without strain. That depth matters more than matching a native speaker's total.

How many words do you need at the other levels?
See the real numbers for A1 · A2 · B1 · B2 · C1.

Sources: Milton and Alexiou, vocabulary size across the CEFR levels · Nation, Vocabulary and the CEFR · ILR, vocabulary size and reading coverage.