Readability Score Checker
Five standard readability formulas, the sentences dragging your score down, and nothing uploaded.
Sentences to shorten
What the scores mean
Flesch Reading Ease runs from about 0 to 100: the higher the score, the easier the text. The four grade-level formulas estimate the US school grade (years of education) a reader needs to follow the text comfortably — 12 means a final-year high school student, 16 a university graduate.
| Reading Ease | Description | Typical reader |
|---|---|---|
| 90–100 | Very easy | Age 10–11 |
| 80–89 | Easy | Age 11–12 |
| 70–79 | Fairly easy | Age 12–13 |
| 60–69 | Plain English | Age 13–15 |
| 50–59 | Fairly difficult | Age 15–18 |
| 30–49 | Difficult | University students |
| 0–29 | Very difficult | University graduates |
Academic writing usually scores lower than everyday writing — 30 to 50 is normal for a university essay, because subject vocabulary is long. That is fine. What matters is not making the text harder than its ideas need: if your score is far below the readings you were set, look at the long sentences the checker lists.
The formulas
All five use the original published constants. W = words, S = sentences, Sy = syllables.
Flesch Reading Ease (Rudolf Flesch, 1948)
Flesch–Kincaid Grade Level (J. Peter Kincaid and colleagues, 1975)
Gunning Fog Index (Robert Gunning, 1952)
A complex word has three or more syllables, not counting proper nouns, hyphenated compounds, or words that only reach three syllables because of an -es, -ed or -ing ending — Gunning's own exclusions.
SMOG grade (G. Harry McLaughlin, 1969)
Polysyllables are words of three or more syllables. SMOG was designed for samples of 30 sentences, so the checker flags shorter texts.
Coleman–Liau Index (Meri Coleman and T. L. Liau, 1975)
L is the average number of letters per 100 words and S₁₀₀ the average number of sentences per 100 words. Because it counts letters rather than syllables, Coleman–Liau does not depend on a syllable counter.
How syllables and sentences are counted
The syllable counter applies English spelling rules — silent final e, -ed endings that are only voiced after t or d, plurals such as boxes and judges, vowel pairs that split (cre-ate, ra-di-o) — plus a list of common exceptions. Tested against the Carnegie Mellon University Pronouncing Dictionary on samples of real prose, it agrees with the dictionary on about 99% of words. Short capitalised abbreviations are counted letter by letter (UK = 2, CSV = 3).
Sentences are counted the same way as in our word counter: they end at full stops, question marks, exclamation marks and ellipses, while abbreviations such as Dr., e.g. and p.m., initials and decimal numbers do not end a sentence. Headings and bullet points without punctuation are joined to the next sentence, which makes scores look harder — remove them before checking if you can.
Different checkers give slightly different scores for the same text because they count syllables and sentences differently. Compare drafts in the same tool rather than comparing tools.
How to make your writing easier to read
- Split long sentences. Sentence length moves every formula. One idea per sentence is a good default; the checker lists every sentence over 25 words.
- Prefer the shorter word when it means the same thing: use for utilise, help for facilitate, about for approximately.
- Keep the technical terms you need. Do not swap precise subject vocabulary for vaguer words just to raise a score — explain the term once instead.
- Cut padding. Phrases such as “it is important to note that” add syllables and nothing else. See how to cut your word count.