This Writing Sample Readability Analyzer is the same analyzer that previously appeared on BlueCentauri.com. I moved it here to my primary domain to accommodate everyone who uses it.
This writing sample analyzer takes a sample of your writing and then calculates the number of sentences, words, and characters in your sample. As it's calculating these statistics it makes estimates as to how many syllables are present in each word. Using these numbers, it then calculates the Flesch Reading Ease, Fog Scale Level, and Flesch-Kincaid Grade Level, which are three of the most common readability algorithms. Simply supply a sample of your writing and then click "Analyze."
The Flesch score relies on the number of syllables and sentence lengths to determine the reading ease of the sample. 20 words per sentence with 1.5 syllables per word yields a Flesch score of 60 and is taken to be plain English. A score in the range of 60-70 corresponds to 8th/9th grade English level. A score between 50 and 60 corresponds to a 10th/12th grade level. Below 30 is college graduate level. To give you a feel for what the different levels are like, most states require scores from 40 to 50 for insurance documents.The Fog Scale:
The Fog scale is similar to the Flesch scale in that it uses syllable counts and sentence length. The scale uses the percentage of 'Foggy' words, those that contain 3 or more syllables.The Flesch-Kincaid Grade Level :
A fog score of 5 is readable, 10 is hard, 15 is difficult, and 20 is very difficult.
The Flesch-Kincaid Grade Level heuristic indicates that the average student in the grade level produced by the scale can read the text.
Questions? Read more about the writing sample analyzer on my FAQ Blog Post