Flesch Readability Score

About this tool

The Flesch Readability Score calculator analyzes text and returns two widely used readability metrics: Flesch Reading Ease (FRE) and the Flesch-Kincaid Grade Level (FKGL). Reading Ease is shown on a 0 to 100 scale — higher scores mean easier to read — and values outside that range are capped at 0 or 100. The Grade Level corresponds to the approximate US school grade needed to understand the text; a result of zero or below is shown as N/A. Both formulas are based on average sentence length and average syllables per word. The tool also shows word, sentence and syllable counts, syllables per word, and a difficulty label so you can see what is driving your score. It needs at least five words, and syllables are estimated with a simple vowel-group rule.

Why use it

• Calculates both Flesch Reading Ease and Flesch-Kincaid Grade Level simultaneously.

• Shows sentence and syllable breakdowns to pinpoint complexity drivers.

• Used by writing tools, academic institutions, and plain-language advocates.

• Runs in real time so you can adjust phrasing and see immediate feedback.

• Standard scoring used by Microsoft Word, Hemingway, and most plain-language tools.

• Helps comply with US federal Plain Writing Act guidelines.

How to use

1. Paste at least five words of text into the Text to analyze box.
2. Click Analyze to see Flesch Reading Ease and Flesch-Kincaid Grade.
3. Review the breakdown stats (words, sentences, syllables, syllables per word) to understand the score.
4. Keep editing: after the first Analyze, the scores update as you type.
5. Aim for sentences under 20 words and most words under 3 syllables for plain-language writing.
6. Compare scores across drafts to confirm your edits actually simplify the text.

When it helps

• Checking whether website copy or blog posts are accessible to your target audience.
• Reviewing government or legal documents for plain-language compliance.
• Academic writing where a target reading level must be met.
• Editing marketing copy to ensure it reads at an appropriate grade level.
• Tuning customer support knowledge base articles to a non-expert audience.
• Auditing healthcare or financial communications for plain-language compliance.

Examples

Tips

• Aim for Reading Ease 60-70 and Grade Level 8 for general web content.
• Government and legal plain-language work targets Reading Ease 65+ or Grade Level 6-8.
• Break long sentences with conjunctions ('and', 'but') into separate sentences to drop the grade level fast.
• Replace polysyllabic Latin/Greek words with shorter Anglo-Saxon equivalents (e.g. 'use' instead of 'utilize').
• Don't optimize too aggressively — over-simplifying technical content can lose accuracy and trust.

Frequently Asked Questions

Glossary

Flesch Reading Ease (FRE)

A 0-100 readability score where higher is easier; calculated from sentence length and syllable density.

Flesch-Kincaid Grade Level (FKGL)

A score corresponding to US school grade level required to comprehend the text.

Syllable

A unit of pronunciation containing a single vowel sound, with or without surrounding consonants.

Plain language

Writing that's clear, concise, and well-organized — readable on first reading.

Sentence

A grammatical unit ending in a period, question mark, or exclamation mark; a key input to readability formulas.

Lexical density

The proportion of content words (nouns, verbs, adjectives) to total words; high density correlates with reading difficulty.