Readability Checker

About the Readability Checker

Paste your text to see how hard it is to read, measured with the standard readability formulas: Flesch Reading Ease, Flesch–Kincaid Grade Level, Gunning Fog, SMOG, Coleman–Liau, the Automated Readability Index and Linsear Write. Each score is shown with its formula and the counts from your text, so you can see exactly where the number comes from. A consensus grade (the median of the six grade-level formulas) gives one figure to aim at.

The checker also lists your hardest sentences and longest words, and highlights them in the text, so you know what to rewrite. Spanish text can be scored with Fernández-Huerta and Italian text with Gulpease.

Common uses

• Checking that public information, instructions and health or legal notices are easy to understand.
• Matching school material to a grade level, or graded readers to learners.
• Editing web copy, blog posts and product descriptions for a wide audience.
• Comparing two drafts: the one with shorter sentences and words usually reads more easily.

The formulas

• Flesch Reading Ease = 206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words). 0–100, higher is easier; 60–70 is plain English. (Flesch, 1948)
• Flesch–Kincaid Grade Level = 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59. (Kincaid et al., for the US Navy)
• Gunning Fog = 0.4 × [(words ÷ sentences) + 100 × (complex words ÷ words)]. Complex words have three or more syllables, not counting proper nouns, hyphenated words or the endings -es, -ed and -ing. (Gunning, 1952)
• SMOG = 1.0430 × √(words of 3+ syllables × 30 ÷ sentences) + 3.1291. Designed for samples of 30 sentences. (McLaughlin, 1969)
• Coleman–Liau = 0.0588 × L − 0.296 × S − 15.8, where L is letters per 100 words and S is sentences per 100 words. (Coleman & Liau, 1975)
• Automated Readability Index = 4.71 × (characters ÷ words) + 0.5 × (words ÷ sentences) − 21.43, counting letters and digits. (Senter & Smith, 1967)
• Linsear Write: one point for every word of 1–2 syllables and three for every word of 3+, divided by the number of sentences; if the result is over 20 halve it, otherwise subtract 2 and halve it. (O'Hayre, 1966)
• Fernández-Huerta (Spanish) = 206.84 − 0.60 × syllables per 100 words − 1.02 × words per sentence. (Fernández Huerta, 1959; some sources print the last term as sentences per 100 words, which would make shorter sentences score as harder, so it is read here as words per sentence, like the Flesch formula it adapts)
• Gulpease (Italian) = 89 + (300 × sentences − 10 × letters) ÷ words. Below 80 is hard for readers with primary-school education, below 60 for middle school and below 40 for readers with a secondary-school diploma. (Lucisano & Piemontese, 1988)

Reading the scores

Grade levels are US school grades: grade 8 is roughly age 13–14, 12 is the last year of school and 13–16 are college years. Flesch Reading Ease bands follow Flesch's own table: 90–100 very easy (5th grade), 80–90 easy, 70–80 fairly easy, 60–70 standard (8th–9th grade), 50–60 fairly difficult, 30–50 difficult (college) and below 30 very difficult (college graduate).

The consensus is the median of the six grade-level formulas, so a single formula that disagrees does not pull it far.

How the text is counted

Sentences and words are found with the Unicode text rules, the same way as in the Sentence Counter: abbreviations such as "Dr." and "e.g." do not end a sentence, and each line break ends one unless you choose Join wrapped lines. Numbers count as words of one syllable. English syllables are counted with a rule-based syllable counter (the open-source syllable library); Spanish syllables with the vowel rules of Spanish spelling (diphthongs, hiatus and accents).

Limitations

• Readability formulas measure only sentence length and word length. They cannot tell whether the text is well organised, accurate or suitable for its readers — a short sentence full of jargon still scores as easy.
• Syllable counts are automatic and can be off by one for some words (for example "science" or "poem"), which moves the scores slightly. Long texts average out these differences.
• Scores for fewer than 100 words, or under 30 sentences for SMOG, are only a rough guide.
• The English formulas were developed for English. Use Spanish or Italian text only with its own formula; the checker warns when the text looks like another language.
• Other tools may give slightly different numbers because they count sentences, words and syllables in their own way.

Privacy

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