Readability Score Calculator

Paste any text to get Flesch-Kincaid, Gunning Fog, SMOG, and more.

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Reading Ease Guide

  • 90–100Very Easy
  • 70–89Easy
  • 60–69Standard
  • 50–59Fairly Difficult
  • 30–49Difficult
  • 0–29Very Difficult

Academic Writing Targets

Flesch Reading Ease30–50
Flesch-Kincaid Grade10–14
Gunning Fog12–16
SMOG Index12–15

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