---
name: readability-measures
description: "Measurable readability targets (Flesch/Amstad, Wiener Sachtextformel, LIX) every text must meet. Use before sending a reply or finishing a document."
---

# Readability Measures

- Check a reply against these targets before you send it, not only a document.
- Measure readability before you publish documentation. Do not rely on gut feeling.
- Target a Flesch Reading Ease of 60 or higher for user documentation (Amstad formula for German).
- Target a Wiener Sachtextformel grade of 8 or lower for German user texts.
- Keep the LIX index under 50 for instructions and under 60 for reference material.
- Keep the average sentence length under 15 words. Flag any sentence over 25 words.
- Keep the share of long words (three or more syllables) low; swap rare long words for short common ones.
- When a passage scores badly: split sentences first, then replace rare words, then cut filler.
- Count the technical terms you leave unexplained: allow at most one per 100 words.
- Count the sentences without a finite verb: allow none outside a table cell or a list item.
- Treat these two counts as part of the score; the formulas above reward short fragments and cannot see either fault.
- Re-measure after every edit; readability targets are acceptance criteria, not suggestions.