Most web copy reads harder than it needs to, and readers quietly bounce when a sentence makes them work. Readability scores turn “this feels clunky” into a number you can act on. Here is what Flesch Reading Ease and Flesch-Kincaid actually measure, and how to push your writing into the easy zone.
What Flesch Reading Ease measures
Flesch Reading Ease returns a score from 0 to 100 where higher means easier. It is driven by just two things: average sentence length (words per sentence) and average word length (syllables per word). Longer sentences and longer words both pull the score down, while short sentences and short words push it up. There is no analysis of vocabulary difficulty or meaning, only structure, which is why the math runs instantly in your browser.
Rough bands to keep in mind:
- 90 to 100: very easy, around 5th grade.
- 60 to 70: plain English, comfortable for most adults.
- 30 to 50: difficult, college level.
- 0 to 30: very hard, academic or legal prose.
Flesch-Kincaid grade level
The same inputs feed a second formula, Flesch-Kincaid Grade Level. Instead of a 0 to 100 scale, it gives a US school grade. A result of 8.0 means an average 8th grader could read the text. It is the more intuitive of the two, because “grade 8” maps directly to an audience. The two scores move together: a high Reading Ease almost always means a low grade level.
What to aim for on the web
For general web content, blog posts, product pages, and documentation, target a Reading Ease around 60 to 70, which lands near grade 8. That is not dumbing down. Plain writing is read faster, shared more, and converts better, and it survives skimming on a phone. Save the dense, low-score prose for legal pages and technical specs where precision outranks ease.
Here is how to check your draft with the Readability Score Checker:
- Open the Readability Score Checker.
- Paste or type your text into the box.
- Read the Flesch Reading Ease and Flesch-Kincaid grade level as they update live.
- Edit the longest sentences and biggest words, then watch the score climb.
Nothing you paste ever leaves your device, so unpublished drafts stay private.
How to improve your score
Because only sentence length and syllable count drive the result, the fixes are concrete:
- Split long sentences. Two short sentences almost always beat one that runs past 25 words.
- Swap big words for small ones. “Use” beats “utilize”, “help” beats “facilitate”.
- Cut filler. “In order to” becomes “to”. Every removed word lifts the average.
- Prefer active voice. It is usually shorter and lands harder.
- Break up walls of text. Short paragraphs and lists reduce average sentence length on the page.
Make a few of these changes, recheck, and you will see the number move fast.
Related tools
- Counting words and sentences as you trim? Use the Word & Character Counter.
- Want to know how long the piece takes to read? Try the Reading Time Estimator.
- Cleaning up headings or copy along the way? See the Case Converter.
Write for the reader you have, not the one with a PhD, and let the score keep you honest.