📖 Readability Score Checker
Analyze your text's readability using five proven formulas. Get grade levels, audience recommendations, and actionable tips.
Understanding Readability Scores
Flesch Reading Ease (0–100)
Developed by Rudolf Flesch, this score rates text from 0 (very difficult) to 100 (very easy). Formula: 206.835 − 1.015 × (words/sentences) − 84.6 × (syllables/words)
- 90–100: Very easy (5th grade) — Comics, simple instructions
- 80–89: Easy (6th grade) — Conversational English
- 70–79: Fairly easy (7th grade) — Consumer magazines
- 60–69: Standard (8th–9th grade) — News articles, most web content
- 50–59: Fairly difficult (10th–12th grade) — Business writing
- 30–49: Difficult (College) — Academic papers
- 0–29: Very confusing (College graduate) — Legal, scientific texts
Flesch-Kincaid Grade Level
Translates the Flesch score into a U.S. school grade level. Formula: 0.39 × (words/sentences) + 11.8 × (syllables/words) − 15.59
Gunning Fog Index
Estimates the years of formal education needed. It penalizes complex words (3+ syllables). Formula: 0.4 × ((words/sentences) + 100 × (complex words/words))
Coleman-Liau Index
Uses character counts instead of syllables, making it more mechanical. Formula: 0.0588 × L − 0.296 × S − 15.8 where L is average letters per 100 words and S is average sentences per 100 words.
Automated Readability Index (ARI)
Uses characters per word and words per sentence. Formula: 4.71 × (characters/words) + 0.5 × (words/sentences) − 21.43