What Is Readability and Why Does It Matter?
Understand the mathematics behind Flesch Reading Ease, sentence complexity, and how clear prose improves conversion rates and user dwell time.
Defining Readability
Readability measures the ease with which a reader can understand a written text. It is not an indicator of intelligence or sophistication; rather, it reflects how efficiently a reader's brain processes information without fatigue or friction.
The Flesch Reading Ease Metric
Developed by Rudolf Flesch in 1948, the Flesch Reading Ease formula evaluates text on a scale from 0 to 100:
Score = 206.835 - 1.015 × (total words / total sentences) - 84.6 × (total syllables / total words)
Higher scores signify text that is easier to read:
- 90–100: Very Easy (5th grade level, e.g. children's books).
- 60–70: Standard / Plain English (8th-9th grade level, optimal for web articles).
- 30–50: Difficult (college level, academic essays).
- 0–30: Very Confusing (dense legal briefs or medical journals).
Practical Strategies to Boost Readability
- Shorten Sentences: Aim for an average of 14–18 words per sentence. Split compound sentences joined by multiple conjunctions.
- Minimize Polysyllabic Jargon: Swap multisyllable abstractions for concrete Anglo-Saxon roots (e.g. use "start" instead of "commence", "help" instead of "facilitate").
- Embrace Active Voice: State who is acting rather than having actions happen to subjects.
Audit Your Writing Instantly
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