Readability Calculator
Check text readability with Flesch Reading Ease, Flesch-Kincaid Grade Level, Gunning Fog, Coleman-Liau, and ARI scores. Instantly analyze word count, sentence complexity, and reading time.
Word Count
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Sentence Count —
Flesch Reading Ease (0–100) —
Flesch-Kincaid Grade Level —
Extended More scenarios, charts & detailed breakdown ▾
Flesch Reading Ease
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FK Grade Level —
Words —
Sentences —
Reading Level —
Professional Full parameters & maximum detail ▾
Word Statistics
Word Count —
Sentence Count —
Avg Words per Sentence —
Avg Syllables per Word —
Complex Words (3+ syllables) —
Time Estimates
Reading Time (min) —
Speaking Time (min) —
Vocabulary & Readability
Unique Words —
Vocabulary Diversity (%) —
Flesch Reading Ease —
How to Use This Calculator
- Paste or type your text into the Text to Analyze field.
- See word count, sentence count, Flesch Reading Ease, and grade level instantly.
- Use Multiple Metrics tab for Gunning Fog, Coleman-Liau, SMOG, and ARI all at once.
- Use Audience Match to check if your text suits your target audience.
- Use the Professional tab for deep analysis: reading time, vocabulary diversity, complex word count.
Formula
Flesch Reading Ease = 206.835 − 1.015×(words/sentences) − 84.6×(syllables/words)
FK Grade Level = 0.39×(words/sentences) + 11.8×(syllables/words) − 15.59
Example
Text: "The cat sat on the mat." → 6 words, 1 sentence, 6 syllables → Flesch = 206.835 − 1.015×6 − 84.6×1 = 116 (capped at 100) → Grade Level ≈ 0 (Very Easy).
Frequently Asked Questions
- Flesch Reading Ease scores text from 0-100. Higher scores mean easier text: 90-100 = Very Easy (5th grade), 60-70 = Standard (8-9th grade), below 30 = Very Confusing (college graduate). Most general content targets 60-70.
- FK Grade Level translates reading difficulty into US school grades. Grade 8 means an 8th grader can understand the text. Most online content targets grade 6-8. Academic papers often score 12-16.
- Gunning Fog measures how many years of formal education are needed to understand the text on first reading. An index of 12 means a high school senior can understand it. Target below 12 for general audiences.
- Average silent reading speed is approximately 200-250 words per minute (wpm) for adults. Speaking speed is around 130-150 wpm. Divide word count by reading speed to get time in minutes.
- Vocabulary diversity (type-token ratio) = unique words ÷ total words. A score of 100% means every word is unique (very short text). Longer texts typically score 40-60%. Higher diversity indicates richer, more varied writing.