Flesch Reading Ease Calculator
Paste a text and choose its language – the calculator counts words, sentences and syllables and works out the Flesch Reading Ease score: with Flesch’s original formula for English and Amstad’s adaptation for German. The higher the score, the easier the text.
Source: Flesch, R. (1948): A new readability yardstick. Journal of Applied Psychology 32(3), 221–233. Updated: .
How it is calculated
The Flesch Reading Ease formula
Score = 206.835 − 1.015 × ASL − 84.6 × ASW, where ASL is the average sentence length (words ÷ sentences) and ASW the average number of syllables per word (syllables ÷ words). Rudolf Flesch published the formula in 1948 in the Journal of Applied Psychology. Long sentences and long words lower the score.
How to check readability
- Paste your text.
- Choose the language – English (Flesch) or German (Amstad formula).
- Read the Flesch score, its rating and the counts of words, sentences and syllables.
Worked example
“The cat sat on the mat. It was a very sunny day.” has 12 words in 2 sentences, so ASL = 6. Ten words have one syllable, “ve-ry” and “sun-ny” have two: 14 syllables, ASW = 14 ÷ 12. Score: 206.835 − 1.015 × 6 − 84.6 × 14 ÷ 12 = 206.835 − 6.09 − 98.7 = 102.045. The formula is not capped at 0–100: very simple texts score above 100, very dense ones below 0.
Score bands
| Score | Reading ease |
|---|---|
| 91–100 | very easy |
| 81–90 | easy |
| 71–80 | fairly easy |
| 61–70 | standard |
| 51–60 | fairly difficult |
| 31–50 | difficult |
| 0–30 | very difficult |
Bands after Flesch (1948), as reproduced in the sources below.
German texts: Amstad’s formula
German words have more syllables on average, so the English formula underrates German texts. Toni Amstad adapted it in his 1978 dissertation at the University of Zurich: Score = 180 − ASL − 58.5 × ASW. Example: “Der Hund bellt. Die Katze schläft auf dem Sofa.” – 9 words, 2 sentences, 11 syllables: 180 − 4.5 − 58.5 × 11 ÷ 9 = 104. We could not verify a published score table for Amstad’s formula, so the calculator shows only the score there; higher still means easier.
How accurate is the syllable count?
Syllables are counted automatically from vowel groups with language-specific rules (for example a silent final “e” in English, or “ei”, “au”, “eu” as one syllable in German). This fits most words, but some – such as “create” – come out one syllable off. Over a longer text this hardly matters. Numbers are not counted as words; hyphenated words count as one word.
What the score does not measure
The score only looks at sentence and word length. Whether a text is well structured, clearly explained or right for its audience is outside its scope: short sentences full of jargon can score well and still be hard to understand.
More text tools: length and reading time with the word counter, title and description with the SERP preview, and AI tokens with the token counter.
Frequently asked questions
What is a good Flesch Reading Ease score?
Higher means easier. Flesch rates 61–70 as “standard”, 71–80 as “fairly easy” and above that as “easy” or “very easy”. Below 50 counts as “difficult”.
Is this the same as the Flesch-Kincaid Grade Level?
No. Flesch-Kincaid converts similar inputs into a U.S. school grade and uses different weights. This calculator shows the Flesch Reading Ease score on its 0–100-style scale.
Can the score be negative or above 100?
Yes. The formula is not capped. Very short sentences with one-syllable words score above 100; long sentences with many long words can drop below 0.
Why is there a separate formula for German?
German words have more syllables on average. Amstad adjusted the weights to 180 − ASL − 58.5 × ASW so that German texts are not rated too hard.
Is my text stored or sent anywhere?
No. The text is analysed only in your browser – it is not sent to a server, not stored and not added to the address bar.
Sources and legal basis
- Flesch, R. (1948): A new readability yardstick. Journal of Applied Psychology 32(3), 221–233
- Amstad, T. (1978): Wie verständlich sind unsere Zeitungen? Doctoral dissertation, Universität Zürich (catalog entry hbz/lobid)
- Formula and Flesch score bands (0–30 very difficult … 91–100 very easy) as reproduced in: Assessing the readability and quality of online written information on epistaxis, Table 1 (PMC12208736)
- Amstad formula FRE (German) = 180 − ASL − 58.5 × ASW as reproduced in: Assessing ChatGPT’s Educational Potential in Lung Cancer Radiotherapy (PMC12349734)
As of: · Editorial policy
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