Flesch-Kincaid Reading Level

From Wikipedia

The Flesch-Kincaid Reading level measures textual difficulty and tells you the grade level of the text.

The Flesch-Kincaid index tells how easy something is to read. It does this by counting the number of syllables in every word and the number of words in every sentence. Then some math is done. The number which results is the grade-school level. For example, the sentence with the score of 8.0 means that someone in 8th grade could understand. Normal writing is usually between the 7 and an 8.

The formula used to calculate the level is as follows:

0.39 x Average No. of words in sentences + 11.8 x Average No. of syllables per word - 15.59 guided tour test