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Kordu Tools
Text Tools Runs in browser Updated 08 Apr 2026

Readability Score

Check text readability using the Flesch Reading Ease score and Flesch-Kincaid grade level.

Paste text above to see the Flesch Reading Ease score and Flesch-Kincaid grade level.
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How to use Readability Score

  1. Paste your text

    Paste or type the text you want to analyse into the input box.

  2. Read the score

    The Flesch Reading Ease score (0–100), readability label, and Flesch-Kincaid grade level are calculated instantly.

  3. Review the detailed stats

    See word count, sentence count, syllable count, average words per sentence, and average syllables per word.

Readability Score FAQ

What is the Flesch Reading Ease score?
The Flesch Reading Ease score (0–100) measures how easy English text is to read. Higher scores mean easier text: 90–100 is very easy (5th grade), 60–70 is standard (8th–9th grade), and 0–30 is very difficult (college graduate level). Most general-audience content should target 60+.

What is the Flesch-Kincaid Grade Level?
The Flesch-Kincaid Grade Level maps the same readability formula to US school grades. A score of 8 means an average 8th grader can understand it. It is commonly used in education and government communications standards.

How can I improve my readability score?
Shorter sentences improve the score most. Aim for an average of 15–20 words per sentence. Using simpler, shorter words (fewer syllables) also helps. Breaking up complex sentences and avoiding jargon both increase readability.

Is this formula accurate for all content types?
The Flesch formula is calibrated for standard English prose. It is less accurate for poetry, highly technical content with necessary jargon, very short texts (under 100 words), and non-English languages. Use it as a guide, not an absolute measure.

Why does the syllable count seem off?
Syllable counting in software is an approximation — English spelling is notoriously irregular. The tool uses common syllable patterns and is accurate for most English words, but may miscalculate for unusual proper nouns, acronyms, and highly irregular words.

Is my text uploaded or stored?
No. All analysis happens in your browser. Your text never leaves your device.

Background

The Kordu Readability Score tool calculates two industry-standard readability metrics for any English text. The Flesch Reading Ease score (0–100) measures how easy your text is to read — higher is easier. Scores of 60–70 represent plain English suitable for general audiences; below 30 is typically academic or technical writing. The Flesch-Kincaid Grade Level maps the same formula to US school grade equivalents — a score of 8 means an 8th grader should be able to understand it.

Both metrics use the same core inputs: average number of words per sentence and average number of syllables per word. Longer sentences and longer words both make text harder to read.

Formulas:

  • Flesch RE = 206.835 − 1.015 × (words/sentences) − 84.6 × (syllables/words)
  • FK Grade = 0.39 × (words/sentences) + 11.8 × (syllables/words) − 15.59

Common uses: checking the readability of blog posts, landing pages, legal documents, educational materials, and marketing copy. Content targeting general audiences should aim for a score of 60+.

All processing runs client-side in your browser. Nothing is uploaded or stored.

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