What are estimates of vocabulary size for each CEFR level?

Question

The CEFR does not specify a vocabulary list or a vocabulary size for each level.

I could find one scientific article attempting this mapping (research paper of Milton J and T. Alexiou (2009), Vocabulary size and the Common European Framework of Reference in Languages), but its conclusion does not make sense to me. They estimate each level requires a linear increase of vocabulary size (an additional 500 to 1000 more words), which I consider is inconsistent with Zipf law and my personal experience.

I found this opinion of a blogger, where size doubles for each level. This makes more sense and is consistent with Zipf law. But it's really just an opinion:

• A1 = 500
• A2 = 1,000
• B1 = 2,000
• B2 = 4,000
• C1 = 8,000
• C2 = 16,000

Would you have any other references that quantify vocabulary size per level? Obviously the estimate may vary a bit with the language or with the method for counting the different lemma. Still I consider it would give a useful perspective, especially when aiming to B2 or C1 while learning with frequency lists or thematic lists.

Answer 1

I haven't found any official source to answer your question, but several members of online forums have explained their methods in estimating what they believe to be the number of vocabulary words you need to know for each CEFR level. The most prominent online resource is the research paper you referenced in your question, so I have excluded that from the websites that I'm listing here.

A user on this forum provides this estimate:

based on this methodology:

According to The Linguist,

There are different ways of measuring levels of proficiency in a language. There’s the European Common Framework of Reference which divides proficiency into six levels from A1 A2, B1 B2, C1 C2. In my view, B2 is where you are fluent, so that’s actually fairly far along...I know in English the difficulty level is roughly grade seven, grade eight and that the biggest factor in the difficulty level of any content is the vocabulary level. Granted, you could have complex sentences and complex structures, but I think the main difference, particularly if we’re talking about levels of fluency, is how many relatively less frequent words are used. In order to be able to call yourself fluent, you needn’t be able to read esoteric literature or scientific papers. You should, however, be able to read the newspaper and to do that you do need at least the vocabulary of someone in grade seven. That’s a fair number of words; it’s got to be 7,000 to 10,000 words in English.

(emphasis mine)

Essentially, the article argues that approximately 7000 - 10000 words must be known in order to achieve a B2 or C1 level of fluency, which falls in line with the first estimate provided if the active and passive vocabulary is added.

Answer 2

There is at least one language test that I have taken that maps its own levels to CEFR levels and that defines the number of words you need to know, namely Hanyu Shuiping Kaoshi (HSK). HSK is a standardised test for Standard Chinese. Hanban, which administers the test for the Chinese Ministry of Education published a mapping between the 6 HSK levels and the 6 CEFR levels.

However, the Association of Teachers of Chinese in German Speaking Countries (Fachverband Chinesisch or FaCh) considers that mapping as too optimistic. So below is a mapping between HSK, the number of required words, and CEFR, based on the mapping by FaCh, which also matches my own experience. (See my website for a mapping that also includes Hanban's take on CEFR levels.)

• HSK 1 : 150 words (pinyin only): no CEFR level.
• HSK 2: 200 words (pinyin only): CEFR A1.1.
• HSK 3: 600 words: CEFR A1.
• HSK 4: 1200 words: CEFR A2.
• HSK 5: 2500 words: CEFR B1.
• HSK 6: over 5000 words: CEFR B2.

If memory serves, HSK 4 is the bare minimum that foreigners need to prove if they want to study a technical subject at a Chinese university; HSK 5 is the minimum level they need for cultural or literary subjects. (This is still quite low compared to the level C1 that foreign students need if they want to study at a German university.)

Of course, CEFR is not based on vocabulary size but on communication skills. Your communication skills depend not simply on your vocabulary but on what you can achieve with the vocabulary and grammatical structures you have mastered. This is why the hunt for vocabulary lists for CEFR is a red herring. In 2009, Françoise Kusseling and Wilfried Decoo looked at how different EU countries defined so-called Profiles and Referentials for CEFR in different languages. They found big discrepancies with regard to vocabulary size depending on the language (or the language institute that defined vocabulary sizes for CEFR levels). The recommended vocabulary sizes varied from 400 to 3300 for level A1, from 800 to 4000 for level B1, and from 1100 to 6800 for level C2.

So it will come as no surprise when I say that I wouldn't want to transfer the above vocabulary sizes for Standard Chinese to other languages.

Answer 3

Vocabulary size and CEFR levels in English based on Vocabulary size and the common European framework of reference for languages by James Milton, Thomaï Alexiou, 2009:

A1  <1500
A2 1500–2500
B1 2750–3250
B2 3250–3750
C1 3750–4500
C2 4500–5000

They checked vocabulary of students that passed Cambridge exams at different levels so their results are empirical.

Vocabulary was checked by XLex test which is limited to 5000 lemmas so above numbers are lower bound.

https://www.researchgate.net/publication/312063998_Vocabulary_size_and_the_common_European_framework_of_reference_for_languages

Another source of gradation is: http://erfoundation.org/wordpress/graded-readers/

UPDATE Two competing publishers, Pearson and Cambridge, provide vocabularies marked per level:

• https://www.english.com/gse/teacher-toolkit/user/vocabulary
• http://www.englishprofile.org/wordlists

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