How to use Readability Score Checker
Check how easy your writing is to read using industry-standard formulas — all computed client-side in your browser with no text ever uploaded. Paste any article, email, or document to instantly see the Flesch Reading Ease score, Flesch-Kincaid Grade Level, and detailed counts for words, sentences, and syllables. Widely used by educators, content marketers, UX writers, and legal plain-language teams to ensure writing matches the target audience's reading level.
- Paste or type your text into the input field.
- Click "Check Readability" — the tool counts words, sentences, and syllables automatically.
- Read your Flesch Reading Ease score (0–100) and the corresponding plain-language interpretation.
- Review the Flesch-Kincaid Grade Level to see the U.S. school-grade equivalent for your text.
- Simplify complex sentences or replace multisyllabic words to raise your score toward your target range.
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Flesch Reading Ease score explained
The Flesch Reading Ease formula, developed by Rudolf Flesch in 1948, is: 206.835 − 1.015 × (total words ÷ total sentences) − 84.6 × (total syllables ÷ total words). Scores range from 0 to 100; higher means easier to read. A score of 90–100 corresponds to roughly a 5th-grade level, understood by most 11-year-olds. A score of 60–70 is considered standard, appropriate for plain-language documents and general-audience content. A score below 30 is rated very difficult, typical of academic journals and legal texts comfortable only for college graduates.
| Score range | Difficulty | Typical reader | Example text type |
|---|---|---|---|
| 90–100 | Very easy | 5th grade (~age 11) | Comic books, simple instructions |
| 70–90 | Easy | 6th grade | Consumer product descriptions |
| 60–70 | Standard | 7th–8th grade | Newspapers, plain-language docs |
| 30–60 | Difficult | High school–college | Academic summaries, manuals |
| 0–30 | Very difficult | College graduate | Legal contracts, research papers |
Flesch-Kincaid Grade Level
The companion Flesch-Kincaid Grade Level formula translates the same variables into a U.S. school-grade equivalent: 0.39 × (total words ÷ total sentences) + 11.8 × (total syllables ÷ total words) − 15.59. A result of 8.0 means the text is appropriate for an 8th-grader. Plain-language guidelines for U.S. government documents recommend a Grade 6–8 target. Plain-language medical writing targets Grade 6 or below. Academic research articles typically score between Grade 13 and Grade 16, corresponding to undergraduate and graduate reading levels.
Worked examples
Plain-language email check
Inputs: 120 words · 8 sentences · 156 syllables
Result: Reading Ease ≈ 81.6 (easy) · Grade Level ≈ 5.6 — fits a general audience
Academic abstract
Inputs: 150 words · 5 sentences · 285 syllables
Result: Reading Ease ≈ 15.6 (very difficult) · Grade Level ≈ 18.5 — graduate-level text
Glossary
- Flesch Reading Ease
- A readability score from 0 (hardest) to 100 (easiest) based on average sentence length and average syllables per word; developed by Rudolf Flesch in 1948.
- Flesch-Kincaid Grade Level
- A U.S. school-grade equivalent (e.g., 8.0 = 8th grade) derived from the same sentence-length and syllable-count variables as the Flesch Reading Ease formula.
- Syllable
- A unit of pronunciation containing a single vowel sound; "computer" has three syllables (com-pu-ter), contributing to a higher difficulty score.
- Average sentence length
- Total words divided by total sentences — a primary driver of readability scores, as shorter sentences are consistently easier to process and understand.
- Grade level
- A measure of text difficulty calibrated to the U.S. education system, where grade 6 corresponds roughly to age 11–12 and is the plain-language target for most public-facing content.
Related reading
Frequently Asked Questions
Why use Readability Score Checker?
- Score text with Flesch Reading Ease and Flesch-Kincaid Grade Level simultaneously in one click
- Pinpoint sentences dragging the average grade level above your plain-language target
- Validate compliance with U.S. government or medical plain-language readability guidelines
- Quantify syllable and sentence counts so you can measure score improvement after edits
Common use cases
- Simplify a blog draft to score Grade 6–8 and reach a broader general-interest audience
- Check a legal disclaimer to confirm it meets plain-language readability requirements
- Compare readability before and after editing a product description for consumer audiences
- Audit a university course syllabus to ensure instructions are clear for incoming students
- Verify that a patient-facing health article achieves a Grade 6 or lower reading level
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