The Spache readability formula is a

readability test Readability is the ease with which a reader can understand a written text. In natural language, the readability of text depends on its content (the complexity of its vocabulary and syntax) and its presentation (such as typographic aspects that a ...

for writing in English, designed by George Spache. It works best on texts that are for children up to

fourth grade Fourth grade (also called grade four, equivalent to Year 5 in England and Wales, and Year 4 in Australia) is a year of Elementary education in some countries. In North America, the fourth grade is the fifth school year of elementary school. Stud ...

. For older children, the Dale–Chall readability formula is more appropriate. It was introduced in 1953 in Spache's "A new readability formula for primary-grade reading materials," (''The Elementary School Journal'', 53, 410–413), and has subsequently been revised.

Calculation

The method compares words in a text to a set list of everyday words. The number of words per sentence and the percentage of unfamiliar words determine the reading age. The original formula was: :

\mbox = \left ( 0.141 \times \mbox \right ) + \left ( 0.086 \times \mbox \right) + 0.839

The revised formula is: :

\mbox = \left ( 0.121 \times \mbox \right ) + \left ( 0.082 \times \mbox \right) + 0.659

Calculation

Further reading