A Flesch-Kincaid calculator that gives your text's grade level and marks the sentences and words that raise it.
Paste your text or a link. You get its reading ease, grade level and reading time, with the sentences and words that make it hard to read marked.
Your text
Paste your text or a link to see its score.
What you paste stays in this browser. The scoring runs on your device; a link is read by my site's reader.
This free Flesch-Kincaid calculator gives your text's grade level: the US school grade a reader needs to follow it.
It also shows the reading ease score, reading time, and the sentences that push your grade up.
Here's where the formula comes from, what grade to aim for, and how to bring yours down.
What is the Flesch-Kincaid grade level?
The Flesch-Kincaid grade level turns a text's sentence length and word length into a US school grade. A score of 8 means an eighth grader can follow it.
J. Peter Kincaid and his team built it for the US Navy in 1975, to check training manuals, from Rudolf Flesch's reading ease score. The formula:
0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59
What readability score to aim for
It depends on who reads it, but 2 well-known guides agree on the rough range:
- Microsoft Word says most documents should score 60 to 70 on reading ease, and a grade level of about 7.0 to 8.0 (Microsoft Support).
- The NHS writes for a reading age of 9 to 11, which is about US grade 4 to 6, with sentences of up to 20 words and paragraphs of up to 3 sentences (NHS service manual).
Experts reading about their own field can take more, so pick who it's for above and the checker holds your text to that range.
Flesch-Kincaid and Flesch reading ease
They use the same 2 counts. Reading ease runs from 0 to 100, higher is easier; grade level is a school year, lower is easier. So a reading ease of 60 to 70 is about grade 8 to 9.
How to make your writing easier to read
The formulas only count 2 things, sentence length and word length, so those are the 2 levers:
- Split long sentences. Anything over 20 words is a candidate. 1 idea per sentence.
- Use the short word. "Use", not "utilize". "Start", not "commence". "Help", not "assist".
- Say who does what. "The team wrote the report", not "The report was written".
- Cut adverbs that add nothing. "Very", "really", "actually" rarely earn their place.
- Keep paragraphs short. 3 sentences or fewer reads well on a phone.
- Writing for the formula, not the reader: short choppy sentences can score well and still read badly
- Swapping every long word: some ideas need their exact term, like "photosynthesis" in a biology post
- Trusting 1 score: check the marked sentences, since the score is only an average
How to check readability in Microsoft Word
Word has the same 2 Flesch scores built in, shown after a spelling and grammar check (Microsoft Support):
This checker gives you the same 2 scores in your browser, plus 4 more formulas, reading time, and the exact sentences to fix.
Flesch-Kincaid Calculator FAQs
Questions about the Flesch-Kincaid calculator? Here's what to know.
About 7 to 8 for most readers, the range Microsoft Word recommends. Health and public information aims lower, around grade 4 to 6.
It's 0.39 times the words per sentence, plus 11.8 times the syllables per word, minus 15.59.
J. Peter Kincaid and colleagues, for the US Navy in 1975, building on Rudolf Flesch's 1948 reading ease score.
Yes, the Flesch-Kincaid calculator is free, with no sign-up. The scoring runs on your device.
What you paste into the Flesch-Kincaid calculator stays in your browser, so it's there when you come back. The text isn't sent to a server, except a link, which my site's reader opens for you.
The Flesch-Kincaid calculator gives word counts and reading time in any language, but the formulas were built for English, so its scores are for English text.
For writing, the headline analyzer scores your headline against real A/B tests, and the subject line tester checks your email subject. See all my free tools.
Navid Moazzez
AI business strategist & AI OS builder
Navid Moazzez helps creators and founders master AI and build their own AI Operating System (AI OS) to automate their business and life.
Navid.me is reader-supported. When you buy through links on this site, I may earn an affiliate commission. Learn more.
More free tools
Bluesky
Apple Books
Amazon
Free AI newsletterThe most actionable AI newsletter for founders
Every week, get proven AI strategies, curated tools, and step-by-step systems to grow your audience, create better content, and build a profitable creator business.
No fluff, no filler, no BS. Just five minutes each week that might level up your online business and life.
P.S. Sign up now to get free access to my ultimate AI tools guide for creators.
