Check Flesch-Kincaid readability of your text
Built & maintained by Pappu Venkata Subbi Reddy, founder of Clacify · Updated August 2026
The Readability Score tool analyses a block of text and scores how easy it is to read, using the Flesch Reading Ease and Flesch-Kincaid Grade Level formulas — two of the most widely used readability metrics, both derived from average sentence length and average syllables per word. Paste or type your text and it instantly returns a 0–100 Reading Ease score (higher means easier to read), an estimated US school Grade Level, and supporting counts — words, sentences, characters, syllables, and estimated reading time at 200 words per minute. It's built for writers, students, and content editors who want an objective, quick check on whether their writing is plain enough for a general audience before publishing it.
Sentences are counted by splitting on ".", "!", and "?"; words are counted as sequences of word characters. Syllables are estimated with a lightweight heuristic rather than a dictionary lookup: for each word, every vowel letter (a, e, i, o, u, y) is counted, a single trailing "e" is dropped (the common "silent e" case, as in "like" or "make"), and the result is floored at a minimum of one syllable per word. This is a reasonable approximation for most everyday English but it counts vowel letters rather than vowel sounds, so it can overcount syllables in words with adjacent vowels that form a single sound — "beautiful" (actually 3 syllables) counts as 5 vowel letters, for example — which means the score is a solid guide, not a laboratory-precise measurement. From the average sentence length (ASL, words per sentence) and average syllables per word (ASW), the tool computes Flesch Reading Ease = 206.835 − 1.015×ASL − 84.6×ASW, and Flesch-Kincaid Grade Level = 0.39×ASL + 11.8×ASW − 15.59 — the original published formulas, both floored at 0 so very simple text can't return a negative or nonsensical score. Reading time is estimated at the common baseline of 200 words per minute.
| Score | Level | Roughly matches |
|---|---|---|
| 90–100 | Very Easy | Comic books, very simple text |
| 70–89 | Easy | Conversational English, most fiction |
| 60–69 | Standard | General web content, most blog posts |
| 50–59 | Fairly Difficult | Slightly technical or formal writing |
| 30–49 | Difficult | Academic or specialist writing |
| 0–29 | Very Difficult | Dense legal, scientific, or bureaucratic text |
These are Rudolf Flesch's original published bands. For general web content, most style guides target 60–70 — readable by the widest possible audience without sounding dumbed-down.
Reading Ease and Grade Level use the same two inputs (sentence length and syllables per word) but present the result on opposite scales — a higher Reading Ease score means easier text, while a higher Grade Level means harder text (it estimates the US school grade a reader would need to comfortably follow it). A Reading Ease score in the 60s roughly corresponds to a Grade Level around 8, which is the commonly cited sweet spot for general-audience web writing — plain enough to be widely accessible without reading as simplistic.
Both formulas reward exactly two things: shorter sentences and shorter (fewer-syllable) words. Splitting a 30-word sentence into two 15-word sentences improves the score more than almost any word-choice change, and swapping a multi-syllable word for a one-syllable synonym ("use" instead of "utilise") does the same on the vocabulary side. This is also the formula's real limitation — it has no sense of clarity, logic, or jargon beyond syllable count, so a text can score "easy" while still being confusing, or score "difficult" purely because it uses long but perfectly ordinary words like "information" or "organization".
Because the tool counts vowel letters rather than looking up real pronunciation, it's most accurate on ordinary English prose and least accurate on text with unusual vowel clusters, proper nouns, or abbreviations. If your score looks off for a short passage, check whether it contains several such words — a longer passage averages this noise out, which is why the formulas are more meaningful for a paragraph or more than for a single sentence.
Flesch-Kincaid scores range from 0 (very difficult) to 100 (very easy). Scores 60–70 are ideal for general web content (readable by most adults). Scores above 80 are for simple content like children's books. Scores below 30 are professional/academic level. Most successful blog posts and marketing copy score between 60–75.
Use shorter sentences (15–20 words average). Use simpler, everyday words instead of complex vocabulary. Break up long paragraphs into smaller ones. Use bullet points and headers. Avoid passive voice. The Hemingway App and Clacify's Readability Score both help identify difficult sentences highlighted for revision.