Readability Score Calculator

Analyze text readability with Flesch-Kincaid, Gunning Fog, SMOG, Coleman-Liau, and grade level scores.

Enter Your Text

36 words - 3 sentences

Estimated Grade Level

College Level

Readability Scores

Flesch Reading Ease

32.5

Difficult - College level

Flesch-Kincaid Grade

11.7

12th Grade (High School)

Gunning Fog Index

13.7

College Level

SMOG Index

11.9

12th Grade (High School)

Coleman-Liau Index

16.0

Graduate Level

Automated Readability

12.0

College Level

Word Count

Sentence Count

Avg Sentence Length

12.0 words

Avg Syllables/Word

1.92

Total Syllables

Complex Words (3+ syl)

Character Count

210

Avg Word Length

5.8 chars

Formula Reference

Flesch Reading Ease

206.835 - 1.015 * (words/sentences) - 84.6 * (syllables/words)

Higher scores mean easier to read. 60-70 is standard.

Flesch-Kincaid Grade Level

0.39 * (words/sentences) + 11.8 * (syllables/words) - 15.59

Estimates the US school grade level needed to understand the text.

Gunning Fog Index

0.4 * ((words/sentences) + 100 * (complexWords/words))

Complex words are those with 3 or more syllables.

SMOG Index

3 + sqrt(polysyllableCount * (30/sentences))

Best for health literacy. Uses polysyllabic word count (3+ syllables).

Coleman-Liau Index

0.0588 * L - 0.296 * S - 15.8

L = avg letters per 100 words, S = avg sentences per 100 words. Uses character counts instead of syllables.

Automated Readability Index (ARI)

4.71 * (characters/words) + 0.5 * (words/sentences) - 21.43

Uses character counts for easy automated computation.

1. Paste or type your text into the input area for analysis. 2. Review the readability scores from all five formulas displayed side by side - Flesch-Kincaid, Flesch Reading Ease, Gunning Fog, SMOG, and Coleman-Liau. 3. Check the estimated US grade level required to understand your text. 4. Examine the detailed statistics including sentence count, average words per sentence, and percentage of complex words. 5. Revise your text to lower the grade level by shortening sentences and replacing complex words, then re-analyze.

About This Tool

Writing that is easy to read gets more engagement, better comprehension, and wider reach. Our Readability Score Calculator analyzes your text using five established readability formulas - Flesch-Kincaid Grade Level, Flesch Reading Ease, Gunning Fog Index, SMOG Index, and Coleman-Liau Index - giving you a comprehensive picture of how accessible your writing is.

Paste or type your text and instantly see scores from each formula, along with the estimated US grade level needed to understand it. The tool also breaks down key statistics like sentence count, word count, average words per sentence, average syllables per word, and percentage of complex words. These metrics help you pinpoint exactly what makes your text harder or easier to read.

This tool is valuable for content writers aiming for broad audiences (target grade 6-8 for general web content), educators preparing materials for specific grade levels, students checking that their essays match assignment expectations, and marketers who want their copy to be instantly understandable. Lowering your readability score does not mean dumbing down your content - it means communicating clearly.

Formula / How It Works

Flesch-Kincaid GL = 0.39 x (words/sentences) + 11.8 x (syllables/words) - 15.59. Flesch RE = 206.835 - 1.015 x (words/sentences) - 84.6 x (syllables/words). Gunning Fog = 0.4 x ((words/sentences) + 100 x (complex words/words)).

Frequently Asked Questions

The Flesch-Kincaid Grade Level translates readability into a US school grade level. A score of 8.0 means an eighth grader can understand the text. It uses average sentence length and average syllables per word in its formula. Most general-audience content should target grades 6-8.

Flesch Reading Ease scores range from 0 to 100, where higher is easier. Scores of 60-70 are considered standard and easily understood by 13-15 year olds. Scores above 80 are very easy to read. Most web content should aim for 60 or above.

The Gunning Fog Index emphasizes complex words (three or more syllables) rather than average syllable count. It estimates the years of formal education needed to understand text on a first reading. Business writing should target a Fog Index of 10-12.

Each formula weights different text properties. Flesch-Kincaid focuses on syllable and sentence length. Gunning Fog counts complex words. SMOG counts polysyllabic words. Coleman-Liau uses character counts instead of syllables. Looking at all five gives a more balanced assessment.

For general web content, aim for a grade level of 6-8 (Flesch Reading Ease of 60-70). This does not mean your content is simplistic - it means you use clear sentences, common words, and direct structure. Even complex topics can be explained at a lower reading level.

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