Reading grade level
From TechWriter Wiki
Reading grade level (RGL) is a measure of the comprehensibility of a piece of writing (or other unit of information - typically of at least 100 words excluding headings and other 'non-sentences'), to produce a realistic measurement). The RGL is the level of education (in the U.S. school system) that a person would need to achieve in order to comprehend the text.
For reference, children in the 11th Grade are 16 years old, so if a text has a calculated RGL of 11, then the expectation is that an average 16-year-old (who has not flunked out of school!) or above should be able to comprehend the text, but an average 15-year-old (or below) may not.
Many content creation applications provide utilities for calculating RPG and other readability statistics. A simple online tool into which you can paste text and determine grade level and other readability measurements can be found at Edit Central.
This page has a reading grade level of 11.6, calculated according to the Flesch-Kincaid formula.
