Readability Score Calculator

Analyze your text with 7 proven readability formulas. Get Flesch Reading Ease, Flesch-Kincaid Grade Level, Gunning Fog, Coleman-Liau, SMOG, ARI, and Dale-Chall scores instantly. All processing happens in your browser -- your text never leaves your device.

🎯 Flesch Reading Ease
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out of 100
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Difficult Easy
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📊 Readability Scores
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Flesch-Kincaid Grade
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Gunning Fog Index
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Coleman-Liau Index
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SMOG Index
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Automated Readability
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Dale-Chall Score
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🔎 Text Statistics
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Words
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Sentences
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Paragraphs
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Characters
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Syllables
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Avg Words/Sentence
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Avg Syllables/Word
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Complex Words (3+ syl)
Time Estimates
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Reading Time (238 wpm)
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Speaking Time (150 wpm)
Enter text above and click Analyze Readability to see scores and statistics.

How It Works

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7 Readability Formulas

Get comprehensive readability analysis with Flesch Reading Ease, Flesch-Kincaid, Gunning Fog, Coleman-Liau, SMOG, ARI, and Dale-Chall scores calculated simultaneously from a single text input.

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Grade Level Mapping

Each score is mapped to a U.S. school grade level and reading difficulty interpretation, making it easy to understand who your target audience should be and how accessible your writing is.

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Detailed Statistics

Beyond readability scores, get word count, sentence count, paragraph count, syllable count, average words per sentence, average syllables per word, complex word count, and time estimates.

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100% Private

All analysis runs entirely in your browser using JavaScript. No text is ever sent to a server, stored, or logged. Safe for confidential documents, drafts, and sensitive content.

About Readability Scores

Readability scores are mathematical formulas that estimate how easy or difficult a piece of text is to read. They analyze factors like sentence length, word length, syllable count, and vocabulary complexity to produce a numerical score or grade level. These scores help writers, educators, healthcare professionals, and content creators ensure their text is appropriate for their intended audience.

Why Readability Matters

Clear, readable writing is essential in every field. Studies show that readers are more likely to engage with and understand content written at an appropriate reading level. For web content, readability directly impacts user experience, bounce rates, and conversion rates. In healthcare, patient materials written at a 6th-grade reading level improve comprehension and health outcomes. In legal and government contexts, plain language requirements mandate readability standards for public-facing documents.

How Scores Are Calculated

Most readability formulas use two primary variables: sentence length (average words per sentence) and word complexity (measured by syllable count or comparison to word lists). Longer sentences and multisyllabic words make text harder to read. The Flesch Reading Ease score outputs a 0-100 value, while grade-level formulas like Flesch-Kincaid and Gunning Fog output a U.S. school grade level. The Dale-Chall formula takes a different approach, comparing words against a list of approximately 3,000 words familiar to 4th graders.

Common Use Cases

Content writers use readability scores to ensure blog posts and articles are accessible to their target audience. Technical writers use them to simplify documentation. Teachers use them to select age-appropriate reading materials. Healthcare professionals use SMOG scores to evaluate patient education materials. Legal teams use readability analysis to comply with plain language regulations. Marketing teams use readability scores to optimize email campaigns, landing pages, and ad copy for maximum engagement.

Frequently Asked Questions

What is the Flesch Reading Ease score?
The Flesch Reading Ease score rates text on a 0-100 scale. Higher scores indicate easier readability. A score of 60-70 is considered standard (easily understood by 13-15 year olds), 0-30 is very difficult (university graduate level), and 90-100 is very easy (5th grader level). The formula considers average sentence length and average syllables per word.
What is the Flesch-Kincaid Grade Level?
The Flesch-Kincaid Grade Level translates readability into a U.S. school grade level. A score of 8.0 means the text is suitable for an 8th grader. It uses the same core variables as Flesch Reading Ease (sentence length and syllable count) but outputs a grade level instead of a 0-100 score. Most general-audience writing should aim for a grade level of 7-8.
What is the Gunning Fog Index?
The Gunning Fog Index estimates the years of formal education needed to understand a text on first reading. It considers sentence length and the percentage of complex words (words with 3 or more syllables). A Fog Index of 12 requires a high school senior reading level, while 17+ requires a college graduate level. Newspapers typically score around 11-12.
How does the Dale-Chall formula work?
The Dale-Chall formula uses a list of approximately 3,000 words that 80% of 4th graders understand. Words not on this list are considered "difficult." The formula factors in the percentage of difficult words and average sentence length. If more than 5% of words are difficult, an adjustment constant of 3.6365 is added to the raw score.
How can I improve my readability score?
To improve readability: use shorter sentences (aim for 15-20 words per sentence), choose simpler words with fewer syllables, break long paragraphs into shorter ones, use active voice instead of passive voice, avoid jargon and technical terms when possible, use transition words to improve flow, and replace complex words with simpler alternatives. Aim for a Flesch Reading Ease score of 60-70 for general audiences.
What is the SMOG Index?
SMOG (Simple Measure of Gobbledygook) estimates the years of education needed to understand a text. It counts polysyllabic words (3+ syllables) and uses the formula: 1.0430 * sqrt(polysyllables * 30/sentences) + 3.1291. SMOG is widely used in healthcare to assess patient-facing materials and is considered one of the most accurate readability formulas for determining grade-level readability.
Is my text data safe when using this tool?
Yes, absolutely. This readability calculator runs entirely in your browser using JavaScript. No text data is sent to any server, stored, or logged. All analysis happens locally on your device. You can verify this by disconnecting from the internet and confirming the tool still works perfectly. This makes it safe to use with confidential documents.
What readability score should I aim for?
The ideal readability score depends on your audience. For general public content, aim for a Flesch Reading Ease of 60-70 (8th-9th grade level). For children's content, aim for 90-100 (5th grade or below). For academic or technical writing, 30-50 is acceptable. Most popular novels score between 60-80. Newspapers typically aim for a 6th-8th grade reading level. Government plain language guidelines recommend writing at an 8th grade level or lower.

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