Raygor readability estimate

The Raygor Estimate Graph is a readability metric for English text, developed by Alton L. Raygor (1977).

The U.S. grade level is calculated by the average number of sentences and letters per hundred words. These averages are plotted onto a specific graph where the intersection of the average number of sentences and the average number of letters/word determines the reading level of the content. Note that this graph is very similar to the Fry Readability Formula's graph.

This formula and graph are often used to provide a common standard by which the readability of documents can be measured. It is sometimes used in secondary education.

The Formula

• Extract a 100-word passage from the selection. If the material is long, take a subsample from the beginning, middle, and end.
• Count the number of sentences in each passage. Count a half sentence as .5.
• Count the number of words in each passage containing six or more letters.
• Find the point on the Raygor Estimate Graph.

Dedicated Readability Software

Readability Studio

Readability Studio offers the Raygor Estimate Graph, as well as many other readability tests.