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Calculate the percentage of content words (vs. common function words) in any text.
50.0%
Lexical density (Ure, 1971) measures how much of a text is made up of "content words" (nouns, verbs, adjectives, adverbs carrying meaning) versus common function words (the, and, of, is, etc.) -- a standard linguistics measure of information density.
Paste your text. Lexical density and the underlying word counts appear instantly.
Lexical Density = (content words / total words) × 100
This calculator does not analyze grammar or tag parts of speech. Instead it uses a fixed list of roughly 130 common English function words, including articles, pronouns, prepositions, conjunctions, and forms of "be", "have", and "do". Every word not on that list is counted as a content word. The text is lowercased and split into words made of letters, digits, and apostrophes, so numbers count as content words, and contractions are compared as whole tokens.
This is a practical approximation of the linguistic idea. A strict linguist might classify some listed words differently, or treat certain verbs such as auxiliaries differently from this tool. The result is consistent and repeatable, which makes it good for comparing drafts, but it will not exactly match a hand-coded academic analysis.
Take the hypothetical sentence: "The team is planning a new campaign for the spring launch." That is 11 words. The function words on the tool's list are the, is, a, for, and the again, making 5. The remaining 6 words (team, planning, new, campaign, spring, launch) are content words.
Lexical density = 6 / 11 x 100 = 54.5%
Now compare a more casual version: "So we are going to do it for the launch." Here nearly every word is on the function list, and only "going" and "launch" would count, giving a much lower density. The difference shows how the measure separates dense, information-heavy phrasing from conversational filler.
Writers use lexical density to sense whether a piece leans too airy or too crammed. If a product description scores very low, it may be full of filler phrasing that could be replaced with specific details. If a help article scores very high, it might benefit from a few more linking words and short explanatory phrases so that steps flow naturally. Language learners and teachers can also compare a learner's written output with model texts to see how information density differs between styles.
Treat the number as a prompt for editing choices rather than a target to hit. Clarity for your intended reader matters more than any percentage.
Written text (e.g. academic prose) is typically higher (often 40-60%+), while casual spoken language tends to be lower -- it's a comparative measure more than a pass/fail score.
No. It treats every word outside its fixed function-word list as a content word, without any grammatical tagging.
Yes, digits are part of the word pattern and are not on the function-word list, so numbers raise the content-word count.
Every word counts toward the total, so adding a few function-heavy words lowers the percentage and adding content-heavy words raises it. Short texts show the biggest swings.
Not automatically. It signals denser information, which suits abstracts and headlines, but conversational content usually reads better with a lower value.
Reference: Google Search Central