A word count tells you how long your writing is. A readability score tries to tell you something harder: whether people will understand it. It's a genuinely useful signal — as long as you know what it's actually measuring.
The formula is simpler than you'd think
Flesch Reading Ease is built from just two inputs: average sentence length, and average syllables per word. That's it. Long sentences and long words push the score down; short ones push it up. The output is a 0–100 scale where higher means easier.
Flesch–Kincaid grade level uses the same two inputs, rearranged to produce a US school grade instead. A grade level of 8 suggests an average 8th grader could follow it.
Reading the score
- 90–100 — very easy, around 5th-grade reading level.
- 60–70 — plain English, comfortable for most adult readers. This is the target for most web writing.
- 50–60 — fairly difficult, roughly high-school level.
- 30–50 — difficult, typically college-level academic or technical writing.
- Below 30 — very difficult, dense academic prose.
For general audiences — marketing pages, help articles, emails, most blog posts — aiming for grade 7–9 keeps writing clear without sounding condescending.
Where these scores mislead
Because the formula only counts sentence length and syllables, it has real blind spots. It cannot tell whether your writing is logically organised, whether your argument makes sense, or whether you've used a short word incorrectly. A passage of confident nonsense with short sentences will score beautifully.
It also penalises unavoidable technical vocabulary. An article about "authentication" and "configuration" scores as difficult purely because those words are long, even if the surrounding writing is perfectly clear to its intended audience. Treat the score as a prompt to re-read, not a verdict.
Four changes that reliably improve clarity
- Split long sentences. Anything past roughly 25 words is usually two ideas wearing one coat.
- Swap long words for plain ones where the meaning is identical — "use" for "utilize", "help" for "facilitate", "about" for "approximately".
- Cut filler phrases. "In order to" is "to". "Due to the fact that" is "because". They add syllables and nothing else.
- Read it aloud. If you run out of breath or lose your place mid-sentence, your reader will too.
One caveat on syllable counting: most tools, including ours, estimate syllables with pattern rules rather than a full pronunciation dictionary. It's accurate enough to compare two drafts or guide edits, but don't treat a two-point difference as meaningful.