Vocabulary Diversity in TOEFL speaking refers to your ability to use a wide range of vocabulary words in your speech. In the TOEFL speaking section, you are assessed on your ability to use a diverse range of vocabulary words in your responses.
This means using a variety of different words to express your ideas and avoid repeating the same words over and over again. A speaker with high vocabulary diversity will be able to use a wide range of vocabulary words effectively in their speech, which will help them to communicate their ideas clearly and effectively.
What is Vocabulary Diversity in TOEFL® Speaking?
Vocabulary Diversity (VDi) in TOEFL® Speaking is a SpeechRater™ indicator of your language use.
VDi is a measure of how varied your vocabulary is in terms of different forms of speech (e.g., nouns, adjectives, adverbs, etc.).
Stronger speakers tend to
- Use a variety of vocabulary items in their speech.
- Use different word forms accurately.
Your Vocabulary Diversity Score
Your Vocabulary Diversity score is calculated based on the number of word types you use in your speech and the comparison of words used in your speech with responses receiving the maximum score.
Vocabulary Diversity is scored out of 100. Your score is indicated by the “You are here” line.

- This response outscored 76% of the test takers in ETS’s database.
- 24% of the responses scored higher in this one dimension.
- This response is consistent with other TOEFL Speaking responses in the 18-25 range.
Tip: Learn more about how to read My Speaking Score charts, including the Impact score and what the coloured bars mean, in our knowledge base.
Why You Should Care
- Those who score 26+ on TOEFL Speaking have an average VDi score of 81.49.
- VDi is one of the mild predictors of your overall TOEFL speaking score.
Increase Your Score
Make sure you use a variety of word forms in your speech and use them accurately.
On My Speaking Score, remember to check your transcript and the distribution of the word forms you used in your speech.

Remember, Vocabulary Depthis a measure of your language use. It does not have a high impact on your speaking score, but a low Vocabulary Depth score can decrease your overall SpeechRater score.
Check out our blog to learn more about how to improve your score in other dimensions!