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U.S. Department of Health and Human Services
Healthcare Communication

Measuring Readability

Readability measures are primarily based on factors such as the complexity of the printed materials by measuring the number of words in the sentence and the number of letters or syllables per word (i.e., as a reflection of word frequency.) A “score” reflects the grade level of the printed material.

  • The Flesch Reading Ease - The Flesch Reading Ease is one of the oldest and most accurate formulas. It is a simple approach to assess the grade-level of the reader.
  • The Fry Graph Readability Formula - Edward Fry developed readability tests based on graph. This graph-based test determined readability through high school. In 1977, Fry extended the graph to test through the college years.
  • The SMOG Readability Formula - This is a simple method used to determine the reading level of written materials. The SMOG Readability Formula was developed by Harold C. McGraw.

These formulas can be helpful but should not be your only evaluation tool because reading level is only one aspect of readability, and readability formulas are not always accurate with forms that have short sentences or phrases.

Learn more about using readability level reading formulas. [PDF - 263 KB]