How the scores are calculated
Flesch Reading Ease = 206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words)
Flesch–Kincaid Grade = 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59
Both depend only on sentence length and word length. Syllables are counted with a standard English approximation, so scores may differ by a few points from other tools.
| Reading Ease | Roughly means |
|---|---|
| 70–100 | Easy: most adults read it quickly. A good target for most business websites. |
| 50–69 | Fairly easy to fairly difficult: fine for technical or B2B audiences who expect detail. |
| Below 50 | Difficult: academic or legal style. Usually too hard for marketing pages. |
The other checks
- Long sentences: more than 25 words. Not wrong, but a page full of them is tiring.
- Passive voice: phrases like “was built” or “are made”. A pattern-based estimate; check each before changing it.
- Dense paragraphs: more than about 80 words without a break. On a phone that is a wall of text.
How to improve a score
- Split the longest sentences. Look for “and”, “which” and “because” as natural breaking points.
- Swap long words for short ones: “use” for “utilise”, “help” for “facilitate”, “start” for “commence”.
- Put the main point first in each paragraph, then explain.
- Break up dense paragraphs with subheadings or short lists.
- Cut filler. The Vague Language Checker highlights phrases that add length without meaning.
Limits of readability formulas
Formulas cannot tell whether writing is clear, accurate or persuasive. Short sentences full of jargon still score well, and a necessary technical term will pull the score down. Use the score as a warning light and the highlighted sentences as your edit list. Our guide to editing AI-written copy covers the judgement calls formulas cannot make.