What it's for
This tool calculates the readability score of an English text, showing how easy or difficult it is to read. It's useful for writers, teachers, editors and anyone who needs to match a text's complexity to its audience.
The formula used
For English we use the classic Flesch Reading Ease formula: 206.835 − 1.015 × (words/sentences) − 84.6 × (syllables/words). We also show the Flesch-Kincaid Grade Level: 0.39 × (words/sentences) + 11.8 × (syllables/words) − 15.59, which estimates the US school grade level needed to understand the text. The Reading Ease score runs from 0 to 100, where higher means easier to read.
How syllables are counted
Syllables are counted with a heuristic algorithm that counts vowel groups and adjusts for a silent trailing "e" and the "-le" ending (as in "table"). It's an approximation, like in every automated readability tool — it can miss uncommon hiatus cases (e.g. "idea", "create"), but it gets the large majority of common words right.
Interpretation bands
These are the well-known standard Flesch Reading Ease bands.
| Score | Level |
|---|---|
| 90-100 | Very easy |
| 80-89 | Easy |
| 70-79 | Fairly easy |
| 60-69 | Standard |
| 50-59 | Fairly difficult |
| 30-49 | Difficult |
| 0-29 | Very confusing |
Frequently asked questions
Is the syllable count perfectly accurate?
No — it's a heuristic approximation based on counting vowel groups, which is standard for this kind of tool. It gets the large majority of words right but can be off on irregular hiatus cases.
What is the Flesch-Kincaid Grade Level?
It estimates the US school grade level (e.g. 8.0 means an 8th-grader should be able to understand the text) needed to comprehend the text, using a different weighting of the same word/sentence/syllable counts.
How much text should I paste?
Ideally one or more full paragraphs (at least 100 words), so the average words-per-sentence and syllables-per-word are representative.
Does the tool handle abbreviations correctly?
Sentence counting splits on periods, exclamation and question marks. Common abbreviations (e.g. "Mr.", "etc.") can cause an extra sentence to be counted, which may slightly skew results in text with many abbreviations.