How to Improve Your Readability Score

What Does Flesch-Kincaid Actually Measure?

The Flesch Reading Ease formula was developed by Rudolf Flesch in 1948. It produces a readability score from 0 to 100. This readability score is based on just two things: how long your sentences are and how many syllables your words have.

Higher scores mean easier to read. Lower scores mean harder. Importantly, the formula does not measure vocabulary sophistication, logical structure, accuracy, or whether your content is actually useful — just sentence length and word complexity.

What Score Should You Aim For?

• 70–80 — plain English, easily readable by most adults. Good target for blog posts, emails, product descriptions.
• 60–70 — standard. Suitable for general-audience journalism and professional writing.
• 50–60 — fairly difficult. Common in quality newspapers and business reports.
• 30–50 — difficult. Academic journals, legal documents, technical manuals.
• Below 30 — very difficult. Medical literature, advanced academic papers.

For most online content — blog posts, landing pages, help articles — aim for 60 or above. Google has confirmed that readability is a factor in how search results are evaluated, and content that is difficult to read tends to have higher bounce rates, which negatively affects rankings.

Five Ways to Improve Your Score

1. Shorten your sentences

Average sentence length has the strongest impact on your score. Aim for an average of 15–18 words per sentence. This does not mean every sentence should be 15 words. Variety is important for rhythm. It means that sentences of 30+ words should be the exception, not the norm.

Use the Clarity Highlighter to find sentences over 25 words and get suggestions for where to split them.

2. Replace polysyllabic words

Words with many syllables drive your score down. "Utilise" (4 syllables) scores worse than "use" (1 syllable). "Approximately" (6 syllables) scores worse than "about" (2 syllables). This is not about dumbing down — it is about choosing the clearest available word.

3. Use contractions in informal writing

Contractions (you're, it's, we've, don't) reduce syllable count and make text feel more conversational — which improves both readability scores and engagement. Use them freely in blog posts and emails. Avoid them in formal reports and legal documents.

4. Break up long paragraphs

While paragraph length does not directly affect the Flesch score, it affects perceived readability significantly. Long paragraphs slow readers down and increase cognitive load. Aim for 3–4 sentences per paragraph for online content.

5. Remove redundant clauses

Relative clauses and parenthetical phrases add length without adding proportional meaning. "The software, which was developed in 2019 and has since been updated twelve times, calculates results automatically" is harder to read than "The software calculates results automatically. It was first released in 2019." Same information, better score, easier to read.

The Flesch-Kincaid Grade Level Score

Alongside the readability score, the Flesch-Kincaid Grade Level formula estimates the US school grade needed to understand your text. Both scores together give you a fuller picture of your overall readability score. A score of 8 means an eighth-grader can read it. For general online content, grade 6–9 is the target range. The toolkit shows both the grade level and your readability score as you type — so you can see the impact of every edit.

Readability score by content type

Different content types have different readability targets. A children's educational site should aim for a Flesch Reading Ease score above 80. A general blog or news site performs best between 60 and 70. Professional reports and legal documents regularly fall below 40, which is normal for their audience. Matching your readability score to your audience is more important than hitting any specific number.

For SEO content, Google's own guidelines favour clear, accessible writing. Pages with higher readability scores tend to have lower bounce rates, which over time can support better rankings. This is not a direct ranking factor — but clear writing keeps readers on the page longer, and engagement is a signal algorithms measure.

Tools to check your readability score for free

The SmartWriteTools readability checker calculates your Flesch Reading Ease and Flesch-Kincaid Grade Level in real time as you type. Paste your text and the score updates with every keystroke — no sign-up, no data sent to any server. The live grade level display in the stats bar shows your current reading level so you can track it as you edit.

For a deeper analysis, the Clarity Highlighter shows every sentence over 18 words colour-coded by length, with suggestions for where to split the longest ones. Combined with the readability score, it gives you a precise target to edit toward rather than a vague sense that your writing is "too complex".