If you've ever used a word processor or a readability tool, you've probably encountered a Flesch-Kincaid score. But what does it actually mean? And should you be trying to improve yours?
The Flesch-Kincaid readability tests are a pair of formulas designed to assess how easy or difficult a piece of English text is to read. They were developed by Rudolf Flesch and J. Peter Kincaid in the 1940s and 1970s respectively, originally for the US Navy to assess the readability of training manuals.
Today they're used across publishing, education, healthcare, legal writing, and web content — anywhere that clear communication matters.
There are actually two related but distinct scores:
The Flesch Reading Ease formula produces a score between 0 and 100. The higher the score, the easier the text is to understand.
| Score | Difficulty | Typical Reader |
|---|---|---|
| 90–100 | Very Easy | Age 11 and under |
| 80–90 | Easy | Age 11–12 |
| 70–80 | Fairly Easy | Age 13–14 |
| 60–70 | Standard | Age 15–16 |
| 50–60 | Fairly Difficult | Age 16–18 |
| 30–50 | Difficult | University level |
| 0–30 | Very Difficult | Professional / academic |
The Flesch-Kincaid Grade Level formula converts the same measurements into a US school grade equivalent. A score of 8 means the text is appropriate for a US eighth-grader (roughly age 13–14). A score of 12 corresponds to a high school senior.
This is the formula used by Microsoft Word when it shows you a readability score, and it's the basis for the reading level shown in WordCountPro.
Both Flesch-Kincaid formulas are based on just two variables:
Longer sentences and longer words both increase difficulty. Shorter sentences and simpler vocabulary improve readability. That's the core insight — and it's why writing guides consistently advise writers to use shorter sentences and plain language.
The right target depends entirely on your audience and purpose:
| Content Type | Recommended Grade Level | Reading Ease Target |
|---|---|---|
| General web content | Grade 6–8 | 60–70 |
| News articles | Grade 8–10 | 50–70 |
| Marketing copy | Grade 6–8 | 60–80 |
| Academic writing | Grade 12+ | 30–50 |
| Legal documents | Grade 14+ | 20–40 |
| Children's content | Grade 2–5 | 80–100 |
For most blog posts and website content, a grade level of 6 to 8 and a reading ease score of 60 to 70 is the sweet spot. This makes your content accessible to the vast majority of adult readers without feeling dumbed down.
The Flesch-Kincaid formulas are useful but not infallible. There are several important limitations to be aware of:
In WordCountPro: The reading level shown is based on the Flesch-Kincaid Grade Level formula. We convert the numerical grade to a label — Easy, Standard, Intermediate, Advanced, or Academic — to make it immediately meaningful. Check your text's reading level →
If your content is scoring at a higher grade level than your target audience requires, here are the most effective ways to bring it down:
WordCountPro shows your Flesch-Kincaid reading level alongside word count, character count and reading time.
Check Reading Level →