Count the essay's total number of words and sentences. Divide the number of words by the number of sentences to find the average sentence length.
Count each syllable of the essay's words. Divide the total number of syllables by the number of words you found earlier. The quotient of this division is the average number of syllables per word.
Multiply the average sentence length by 1.015, the average number of syllables per word by 84.6 and subtract them both from 206.835. The result is the reading ease score, expressed on a zero to 100 scale. Easy to understand essays receive scores between 60 and 70, while scores near 100 denote an overly simplistic text.
Multiply the average sentence length by 0.39 and the average number of syllables per word by 11.8. Add the products of the two multiplications and subtract 15.59 from the result of the addition. The result is the Flesch-Kincaid Reading Age.
Link the FKRA to it's corresponding grade level. The test rates the essay on a U.S. school grade level. A score of 7.2 means a seventh grader can understand the essay.