Readability Scores: What They Really Tell You About Your Writing

Readability scores promise a single number for how easy your writing is to digest. Used wisely, they catch genuinely convoluted sentences. Used blindly, they produce writing that feels patronizing and shallow. Here is how to interpret the metrics and keep your voice.

What the numbers mean

• Flesch Reading Ease — 0 (hardest) to 100 (easiest). 60-70 is plain English; 90+ is a children's book.
• Flesch-Kincaid Grade Level — maps the same text to a U.S. school grade. Grade 8 means an average 13-14 year old can read it with ease.

What actually drives the score

The formulas count two things: average sentence length and average syllables per word. Short sentences with short words score well. That means dense technical terms sink the score even when the writing is perfectly clear to its audience.

When the score lies

• Technical documentation for developers — jargon is appropriate and expected
• Legal and financial content where precision matters more than flow
• Marketing copy aimed at niche professionals who know the vocabulary

A practical target

For general web content, aim for a grade level of 8-10 (Flesch 60-70). For developer docs and B2B technical writing, grade 12-14 is often right. The goal is not the lowest number; it is clarity for the actual reader.

Use scores to catch outliers

The real value is spotting the one paragraph that drags a page into grade 15 while the rest sits at grade 9. That outlier is usually a run-on sentence or a jargon wall. Rewrite just that passage rather than dumbing down the whole page.

A readability checker reports the score and the sentence-level breakdown, letting you target the worst offenders without losing nuance.