Lexical density calculator

Find out how much of your text is doing the heavy lifting: the share of content words that carry meaning, versus the grammatical glue between them.

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Lexical density

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Content words
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Lexical diversity (TTR)
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Content words marked

Content words will be marked; the unmarked words are function words.

Why lexical density matters for readability

Readability formulas measure length. Lexical density measures packing. Two sentences of the same length can differ a lot: “We think that it is going to rain on the day of the race” (low density) against “Forecasters predict heavy race-day rainfall” (high density). The second is shorter but asks more of the reader per word.

For web content, density in the 40s to low 50s usually reads comfortably. If yours is above 60%, try unpacking noun stacks (“customer onboarding process improvement” becomes “improving how we onboard customers”). Then re-check the readability score.

References: Ure, J. (1971). “Lexical density and register differentiation.” In Perren & Trim (eds.), Applications of Linguistics. Halliday, M. A. K. (1985). Spoken and Written Language. Deakin University Press.

Lexical density FAQ

What is lexical density?

The percentage of words in a text that carry meaning (nouns, main verbs, adjectives, adverbs), as opposed to grammatical function words such as “the”, “of”, “is” and “they”. The idea comes from the linguist Jean Ure (1971) and was developed by Michael Halliday.

What is a normal lexical density?

Spoken English usually sits below about 40%; written English is typically 40–60%. Dense academic or technical writing can go higher. Very high density packs in information but is harder to read.

How is it calculated here?

Content words ÷ total words × 100. We classify a word as a function word if it is on a list of common English pronouns, articles, prepositions, conjunctions, auxiliary verbs and determiners; everything else counts as content. Numbers are excluded from the content count.

What is the difference between lexical density and lexical diversity?

Density measures how much of the text is content words. Diversity (type-token ratio) measures how many different words you use: unique words ÷ total words. We show both.