Fry Readability Formula



The Fry readability formula (or Fry readability graph) is a readability metric for English texts, developed by Edward Fry.

The grade reading level (or reading difficulty level) is calculated by the average number of sentences (y-axis) and syllables (x-axis) per hundred words. These averages are plotted onto a specific graph; the intersection of the average number of sentences and the average number of syllables determines the reading level of the content.

The formula and graph are often used to provide a common standard by which the readability of documents can be measured. It is sometimes used for regulatory purposes, such as in healthcare, to ensure publications have a level of readability that is understandable and accessible by a wider portion of the population.

Formula
To calculate a grade level score:


 * 1) Randomly select three separate 100 word passages. (Count every word including proper nouns, initializations, and numerals.)
 * 2) Count the number of sentences in each 100 word sample (estimate to nearest tenth).
 * 3) Count the number of syllables in each 100 word sample. (Each numeral is a syllable. For example, 2007 is 5 syllables -- two-thou-sand-se-ven -- and one word.)
 * 4) Plot the average sentence length and the average number of syllables on the graph.
 * 5) The area in which it falls is the approximate grade