Last updated: March 2026
Understanding Readability Scores
Readability scores give you an objective measure of how easy your writing is to understand. They were originally developed for educators to match reading materials to student ability levels, but today they are essential for anyone who writes for an audience — marketers, UX writers, journalists, healthcare communicators, and technical authors.
The average American reads at an 8th-grade level. Most successful web content is written at a 6th to 8th grade reading level, which maximizes both comprehension and engagement.
The core idea behind every formula is the same: shorter sentences and simpler words are easier to read. Longer sentences demand more working memory. Longer words tend to be more abstract or specialized. By measuring these factors, readability formulas predict how much education a reader needs to comfortably understand the text.
Different audiences require different reading levels. The average American adult reads at about an 8th grade level. Most newspapers write at grade 8, and plain-language advocates recommend grade 6 for public-facing health and government information. Web content that is easy to scan — short paragraphs, simple vocabulary, clear structure — consistently outperforms dense, academic-style prose in user engagement metrics.
No single formula is perfect. Flesch-Kincaid counts syllables, Coleman-Liau counts characters, and Gunning Fog focuses on multi-syllable "complex" words. Using multiple formulas together gives a more reliable picture. If Flesch-Kincaid says grade 9 but SMOG says grade 11, you know the text is in the high-school range but contains many polysyllabic words. The consensus score on this tool averages all grade-level formulas to give you a single, balanced number.
Beyond the scores, pay attention to actionable metrics like average sentence length and complex word percentage. If your average sentence is over 20 words, start splitting. If more than 10% of your words have three or more syllables, look for shorter synonyms. These concrete changes directly improve every readability score.
Frequently Asked Questions
What is a readability score?
A readability score is a numerical estimate of how easy or difficult a piece of text is to read. Different formulas like Flesch-Kincaid, Gunning Fog, and SMOG use factors like sentence length, word length, and syllable count to calculate a grade level or ease score. Lower grade levels mean simpler text.
What grade level should I target?
For general web content and marketing, aim for grade 6-8 (roughly 6th to 8th grade level). Newspapers write at grade 8. Health information should be grade 6 or below. Technical documentation for experts can be grade 10-12. Academic papers are typically grade 12+.
What is a good Flesch Reading Ease score?
A Flesch Reading Ease score of 60-70 is considered standard/plain English. Scores above 70 are easy to read. Most web content should aim for 60+. Marketing copy performs best at 70-80. Legal and academic text often scores below 30.
How accurate are readability formulas?
Readability formulas are useful approximations, not perfect measures. They rely on surface-level features like word and sentence length. They cannot assess meaning, coherence, or whether the reader has the necessary background knowledge. Use them as guidelines alongside your own judgment.
Why do different formulas give different scores?
Each formula weights different factors. Flesch-Kincaid emphasizes syllable count. Gunning Fog focuses on complex words (3+ syllables). Coleman-Liau uses character count instead of syllables. SMOG specifically counts polysyllabic words. The consensus score averages them all for a more balanced estimate.
Is my text stored or sent to a server?
No. All analysis happens entirely in your browser using JavaScript. Your text never leaves your device. Nothing is stored, logged, or transmitted.