Lexical Diversity Calculator
Measure the vocabulary variety of your writing with the type-token ratio (TTR) and root TTR, and see which words you repeat the most.
Frequently Asked Questions
- What is the type-token ratio (TTR)?
- TTR is the number of unique words (types) divided by the total number of words (tokens). A text of 100 words containing 60 different words has a TTR of 0.60, or 60%. Higher values mean more varied vocabulary.
- What is root TTR and why show it?
- Root TTR (Guiraud's index) divides unique words by the square root of total words. Because plain TTR always falls as a text gets longer, root TTR partially corrects for length and is more stable when texts differ moderately in size.
- Can I compare the TTR of two texts?
- Only if they are about the same length. TTR depends heavily on text length — every text repeats function words like "the" and "of" more as it grows, so a 2,000-word essay will almost always score lower than a 200-word paragraph regardless of writing quality.
- What is a good lexical diversity score?
- There is no universal target — it varies with length, genre, and audience. As a rough guide for passages of a few hundred words, a TTR below 40% suggests noticeable repetition, 40-60% is typical of clear prose, and above 60% indicates a varied vocabulary.
- How are words counted?
- Text is lowercased and split into word tokens (letters, digits, and internal apostrophes), so "The" and "the" count as one type, and "don't" is a single word. Punctuation is ignored. Everything runs locally in your browser.