Readability Checker
Flesch-Kincaid reading ease and grade level for any text
About this tool
This free readability checker measures how easy your text is to understand using three classic formulas: Flesch Reading Ease (FRE), Flesch-Kincaid Grade Level (FKGL), and Gunning Fog Index. It also shows word count, sentence count, syllable count, complex word count, and average sentence length — the raw metrics behind each score. Paste your text and all scores calculate instantly.
Flesch Reading Ease scores range from 0 to 100: 90–100 is very easy (5th grade), 60–70 is standard (8th–9th grade, newspaper level), 30–50 is difficult (college), and below 30 is very difficult (academic/professional). Most content marketing, email, and web copy aims for 60–70. The formula penalizes long sentences and multi-syllable words. Flesch-Kincaid Grade Level converts the same underlying metrics into a US school grade level (7.0 = 7th grade).
Gunning Fog Index measures what education level a reader needs to understand the text on first reading. A score of 12 corresponds to a US high school senior; 17 is a college graduate. The formula counts "complex words" — those with three or more syllables — as a proxy for cognitive load. Most popular novels score 6–8; Harvard Business Review articles average around 14–16; academic journals can exceed 20.
Tips for improving readability: break long sentences into shorter ones (aim for 15–20 words average), prefer common single-syllable words over technical multi-syllable alternatives, use active voice, avoid jargon for general audiences, and use paragraph breaks and headings to reduce visual density. Hemingway App, Grammarly, and this readability checker are all useful tools for diagnosing dense writing.