> ## Knowledge Base Index
> Fetch the complete knowledge base index at: https://help.readable.com/sitemap.xml
> Use this file to discover available pages before exploring further.
> Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash).

# What is the Gunning Fog Index?

The Gunning Fog index is a commonly cited readability scoring formula.  
  
The Gunning Fog formula generates a grade level, typically between 0 and 20. The formula estimates the years of formal education the reader requires to understand the text on first reading.  
  
So, if a piece of text has a grade level readability score of 6 then this should be easily readable by those educated to 6th grade in the US schooling system, i.e. 11-12 year olds.  
  
For more information, please read our blog: [Readability and the Gunning Fog Index](https://readable.io/blog/the-gunning-fog-index/).