Text Complexity Calculator
Analyze vocabulary diversity, lexical density, and overall text complexity using linguistic metrics like Guiraud's index.
Inputs
Results
Lexical Density
40%
How to Use This Calculator
- Paste the text to analyze into the input field.
- Select the complexity metrics to compute: sentence length, lexical density, type-token ratio.
- Review the average sentence length, lexical density (%), and TTR.
- Compare complexity scores across documents to ensure consistency within a corpus.
- Target a lexical density of 40-50% and TTR above 0.4 for engaging but accessible content.
How the result changes with Total Words
| Total Words | Lexical Density |
|---|---|
| 100,001 | 0.2% |
| 350,001 | 0.06% |
| 650,000 | 0.03% |
| 900,000 | 0.02% |
What each input means
- Total Words
- Total number of word tokens in the text.
- Unique Words
- Number of distinct word types (unique forms).
- Total Sentences
- Total number of sentences in the text.
- Avg Syllables per Word
- Average number of syllables per word. English average is ~1.5.
What each result means
- Lexical Density
- Percentage of unique words. Higher values indicate more diverse vocabulary.
- Vocabulary Diversity (Guiraud)
- Guiraud's index: unique words divided by square root of total words.
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersTotal Words = 500, Unique Words = 200, Total Sentences = 25, Avg Syllables per Word = 1.5 = 4 input(s) provided
- Calculate Lexical DensityLexical Density = min(10040 = 40
- Calculate Vocabulary DiversityVocabulary Diversity8.94 = 8.94
- Calculate Average Sentence LengthAverage Sentence Length20 = 20
Engine last updated . Checked against 1 independently-derived test — how we verify calculators.
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