One of the formulas that is similar to the SMOG formula is the Flesch-Kincaid formula.
This index computes readability based on the average number of syllables per word and
the average number of words per sentence. The score in this case indicates a grade-school
level. For example, a score of 8.0 means that an eighth grader would understand the
document. Standard writing approximately equates to the seventh- to eighth-grade level.