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Readability Score Calculator

Paste any text to instantly calculate six readability scores. Understand what grade level your writing targets and optimize for your audience — whether you're writing blog posts, marketing copy, technical docs, or academic papers.

Scores Explained

Flesch Reading Ease — 0 to 100 scale. Higher = easier to read. Most web content should aim for 60-70. Flesch-Kincaid Grade — US school grade level needed to understand the text. Gunning Fog — Years of formal education needed. Accounts for complex words (3+ syllables). Coleman-Liau — Based on characters per word rather than syllables, making it more consistent. SMOG — "Simple Measure of Gobbledygook" — estimates years of education needed, focused on polysyllabic words. ARI — Uses character and word counts instead of syllables for faster computation.

See also: the Featured Snippet Preview to check whether your content's structure will support a paragraph or list snippet; and the Heading Hierarchy Checker to validate the heading outline that complements your readability score.

See also: readability is one input to the Page Experience signal — the Core Web Vitals Cheatsheet covers the performance side, and the Link Health Checker catches anchor-text patterns that hurt comprehension.

When the Score Matters Most

Readability scoring is most useful when the audience and the channel are known in advance. A technical white paper for engineers can sit at Flesch-Kincaid grade 14 and be exactly right; the same number on a consumer landing page is a problem. The scores are calibrated to roughly match a US grade level, so the goal is to match the level to the reader rather than to push every piece down to grade 8.

Three writing contexts where this tool earns its keep: healthcare and public-service communication, where guidelines from the CDC, the Plain Writing Act, and most state health departments target a grade 6 to 8 reading level for the general public; financial product disclosures, where consumer-protection regulators have been increasingly explicit that fine print written above grade 12 will be treated as functionally undisclosed; and email marketing, where independent send-list studies consistently show that subject lines and preview text written below grade 7 outperform their more-elaborate counterparts on open rate. For brand and editorial writing where the voice is the product, the score is informational only — do not let it flatten the prose.

Frequently Asked Questions

What is a good Flesch Reading Ease score?+
60-70 is considered ideal for general web content. 70+ is easy to read (suitable for a broad audience). 30-50 is college-level. Below 30 is academic/professional level.
What grade level should I target for web content?+
For general web content, aim for grades 6-8 (readable by 12-14 year olds). Marketing copy should target grades 4-6. Technical documentation can be grades 10-12.
How are syllables counted?+
The tool uses a rule-based algorithm that counts vowel groups, handles silent e, and accounts for common English patterns. It's approximately 90% accurate — professional linguists sometimes disagree on exact syllable counts.
Do these scores work for non-English text?+
These formulas are calibrated for English. They measure sentence length and syllable count, which have different relationships to difficulty in other languages. Use language-specific readability tools for non-English content.
Which readability formulas does the tool calculate?+
Flesch Reading Ease, Flesch-Kincaid Grade Level, Gunning Fog Index, SMOG Index, Coleman-Liau Index, and Automated Readability Index. The summary shows the median across all six for a robust estimate.
What grade level should I target?+
For general web content, grade 6–8 (Flesch 60–70) hits the sweet spot for broad accessibility. Technical documentation can go higher (grade 10–12). News and marketing copy aim lower (grade 4–6).
Does the score work for non-English text?+
The formulas were calibrated on English and produce less reliable results for other languages. The tool flags this and offers language-specific variants for Spanish (Fernandez-Huerta), German (Wiener Sachtextformel), and French.
Will simpler writing always rank better?+
Generally yes — search engines favour content matching user intent, and most users prefer clearer prose. But matching your audience matters more: technical readers expect technical language. Aim for clarity, not dumbing down.

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