Flesch-Kincaid Calculator
Measure how easy your English text is to read.
Flesch Reading Ease
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Flesch-Kincaid Grade
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Gunning Fog Index
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Sentences
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Paste at least a few sentences of English text to calculate readability. Longer samples (100+ words) give more reliable results.
Flesch-Kincaid Readability Calculator
Check how easy your writing is to read. Paste English text to get the Flesch Reading Ease score, the Flesch-Kincaid Grade Level, and the Gunning Fog Index, plus the sentence, word, and syllable statistics behind them.
The formulas
- Flesch Reading Ease = 206.835 − 1.015 × (words / sentences) − 84.6 × (syllables / words)
- Flesch-Kincaid Grade Level = 0.39 × (words / sentences) + 11.8 × (syllables / words) − 15.59
- Gunning Fog Index = 0.4 × [(words / sentences) + 100 × (complex words / words)]
How to improve your score
- Split long sentences – aim for 15–20 words on average.
- Prefer short, common words over long technical terms.
- Use active voice and concrete examples.
- Break content into short paragraphs and lists.
Readability affects SEO indirectly: easy-to-read pages keep visitors engaged longer. Use the Sentence Counter to find long sentences and the Word Frequency Counter to spot repetition.
Frequently Asked Questions
What is a good Flesch Reading Ease score?
Scores range roughly from 0 to 100; higher is easier. 60–70 is plain English that most adults understand easily and is a good target for websites and marketing. 30–50 is typical for academic papers, and below 30 is very difficult.
How is the Flesch-Kincaid Grade Level calculated?
Grade Level = 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59. The result approximates the US school grade needed to understand the text; for example, 8.0 means an eighth-grade student can read it.
Does it work for languages other than English?
The formulas and the syllable counter are designed for English. Scores for other languages are not reliable because word and syllable lengths differ.