Flesch Kincaid Calculator

Summary

The Flesch-Kincaid Calculator analyzes any English text and returns two industry-standard readability metrics: Flesch Reading Ease (0–100, higher = easier) and Flesch-Kincaid Grade Level (US school grade required to understand the text). Both formulas rely on average sentence length and average syllable count per word. Results update instantly as you type or paste.

How it works

1. Paste or type your text into the input area.
2. The tool counts sentences, words, and syllables automatically.
3. Flesch Reading Ease = 206.835 − 1.015 × (words/sentences) − 84.6 × (syllables/words).
4. Flesch-Kincaid Grade Level = 0.39 × (words/sentences) + 11.8 × (syllables/words) − 15.59.
5. A color-coded interpretation label tells you the target audience.
6. The per-sentence table shows grade level for each individual sentence.

Use cases

• Check whether a blog post or article matches your target reading level.
• Simplify legal or medical documents for a general audience.
• Verify that educational materials suit the intended grade level.
• Optimize marketing copy for maximum clarity and engagement.
• Assess employee communications and internal memos for readability.
• Improve UX copy and onboarding text in software products.
• Grade student writing assignments for readability and complexity.
• Benchmark readability before and after editing a draft.

Frequently Asked Questions