How the scores work
Flesch Reading Ease uses average sentence length and average syllables per word: 206.835 minus 1.015 times words per sentence minus 84.6 times syllables per word. 60 to 70 is plain English; above 80 is very easy; below 30 is hard.
The Flesch Kincaid grade level turns the same inputs into a US school grade. Most marketing copy reads best around grade 6 to 8, even for expert audiences, because people skim.
What to do with the result
Shorter sentences and everyday words raise the score. The formula cannot judge meaning, so a clear sentence with one long technical word is fine. Use the score to find hard passages, not as a target to game.
Questions
What is a good Flesch Reading Ease score?
60 or above is easy for most adults. Landing pages and listings often aim for 60 to 80.
How are syllables counted?
By an English vowel-group estimate, as most readability tools do. It is close for most words and occasionally off by one.
Does readability affect SEO?
Not as a direct ranking score. Clear text keeps readers on the page and is easier for search engines and AI assistants to quote.
Does it work for other languages?
The Flesch formulas were built for English; scores for other languages are not comparable.