Readability checker
Paste your text for the Flesch reading ease score, five grade-level formulas, and a vocabulary sophistication profile, all calculated in your browser as you type.
| Flesch–Kincaid grade | 12.3 |
| Gunning Fog index | 14.4 |
| SMOG grade | 13.4 |
| Coleman–Liau index | 14.1 |
| Words per sentence | 17.3 |
| Syllables per word | 1.80 |
Vocabulary sophistication
Longest recurring words: deprivationconsolidationdeclarativelaboratoryparticipantssignificantlyreorganisation
How the Flesch formula works
Rudolf Flesch published the reading ease formula in 1948; J. Peter Kincaid’s team converted it to a grade level for the US Navy in 1975. Both look at only two things: how long your sentences are and how long your words are, measured in syllables.
Reading ease = 206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words)
Drag the sliders. The syllable term has a weight of 84.6, so a small change in word length moves the score far more than adding a few words to a sentence. That is why swapping “utilise” for “use” helps more than splitting one sentence.
Fairly difficult (10th–12th grade) · grade level 11.1
Typical values: children’s books ≈ 8 words / 1.2 syllables; a newspaper ≈ 20 / 1.5; a journal abstract ≈ 25 / 1.8.
Questions
What is a good Flesch reading ease score for academic writing?
Published research articles usually score between 10 and 40 (“difficult” to “very difficult”). For a student essay, 30–50 is typical. General-audience writing aims for 60 or above. A low score is not a fault in itself, but scores below 20 often mean overlong sentences that can be split.
What is the difference between Flesch reading ease and Flesch–Kincaid grade level?
Both use the same two inputs, words per sentence and syllables per word, with different weights. Reading ease runs from about 0 to 100 (higher is easier). Grade level converts the same inputs to a US school grade: 12 is a high school senior, 16 a college graduate.
How accurate is syllable counting?
Syllables are estimated with vowel-group rules, which are right for most English words and off by one on some (for example “created” or proper nouns). On a paragraph of 100 words or more the effect on the scores is small.
What does vocabulary sophistication measure?
It combines three signals: average word length, the share of words with three or more syllables, and lexical diversity (the moving-average type–token ratio, which rewards not repeating the same words). It is a descriptive measure, not a quality grade.