Readability Score Calculator
Paste any text to get Flesch-Kincaid, Gunning Fog, SMOG, and more.
Reading Ease Guide
- 90–100Very Easy
- 70–89Easy
- 60–69Standard
- 50–59Fairly Difficult
- 30–49Difficult
- 0–29Very Difficult
Academic Writing Targets
What Is Readability?
Readability refers to how easy or difficult a piece of text is to read and understand. It depends on factors like average sentence length, vocabulary complexity, and the proportion of multi-syllable words. Readable writing communicates more effectively — readers understand faster, stay engaged longer, and are more likely to act on what they read.
Readability is important for academic writing, website content, business communications, and education materials. The ideal readability level depends on your audience: a scientific journal article can be more complex, while a public-facing website should aim for broad comprehension.
How Readability Scores Work
Flesch Reading Ease (0–100)
Higher scores mean easier reading. A score of 60–70 is suitable for general audiences. Below 30 is very difficult (academic or professional). Most web content targets 60+. Calculated from average sentence length and average number of syllables per word.
Flesch-Kincaid Grade Level
Returns a US school grade level. Grade 8 means an 8th grader can read it comfortably. Most blog posts aim for Grade 6–8. Academic writing often falls between Grade 12–16. Uses the same inputs as Flesch Reading Ease but outputs a grade rather than a 0–100 score.
Gunning Fog Index
Estimates the years of formal education needed to read the text on first pass. A score of 8 or less is ideal for most general audiences. Scores above 17 indicate very dense, academic text. Complex words (3+ syllables) heavily influence this score.
SMOG Index
The Simple Measure of Gobbledygook estimates the education level required to understand a piece of writing. It is particularly used in healthcare and public health communications. Like Gunning Fog, it penalises polysyllabic words.
Tips to Improve Readability
- Keep sentences short — aim for an average of 15–20 words.
- Use simple, common words instead of complex alternatives where possible.
- Break long paragraphs into shorter ones (3–5 sentences each).
- Use active voice rather than passive constructions.
- Avoid jargon unless writing for a specialist audience.
- Use headings, bullet points, and numbered lists to break up dense text.
Frequently Asked Questions
The Flesch-Kincaid Grade Level estimates the US school grade level needed to understand a text. A score of 8 means an 8th-grader could understand it. For academic writing, a score of 10–14 is generally appropriate.
The Flesch Reading Ease score rates text on a scale of 0–100. Higher scores indicate easier reading. Scores of 60–70 are considered plain English. Scores above 80 are very easy; below 30 are very difficult. Academic and technical writing typically scores 30–50.
The Gunning Fog Index estimates the years of formal education needed to understand a text. It weights sentences and multi-syllable words heavily. A score of 12 equates to high-school level. Most publications aim for a score of 7–8.
SMOG (Simple Measure of Gobbledygook) estimates the years of education needed to understand a piece of writing based on polysyllabic words. It is most accurate for texts with at least 30 sentences. A score of 13 equates to college-level reading.
Use Flesch Reading Ease for a quick overall difficulty check. Use Flesch-Kincaid Grade Level when writing for a specific grade level. Use Gunning Fog for business and professional writing. SMOG is commonly used in health communication and educational materials.
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