Readability scores explained, and why yours is probably fine

Readability formulas measure sentence length and syllable count. That is all. They do not measure clarity, and they certainly do not measure quality.

Used as a diagnostic, they are genuinely helpful. A chapter that suddenly jumps three grade levels above the rest of the book usually contains a passage where you were explaining something you had not fully worked out yourself.

Used as a target, they are destructive. Chopping every sentence to fourteen words to hit a number produces prose that reads like assembly instructions.

The right use is comparative. Look at variance across chapters, not the absolute value. Consistency signals a controlled voice; wild swings signal sections that need another pass.

Manucheck reports readability per section for exactly this reason, and always alongside the qualitative findings that explain what caused the number.