The Flesch-Kincaid readability test calculates readability by comparing the number of words to the number of sentences and the number of syllables to the number of words. The Flesch reading ease test is most accurate for text intended for 5th graders and beyond.

The Gunning fog index calculates readability by counting the number of words relative to the number of sentences, and the number of words with 3 or more syllables to the total number of words. The Gunning fog index is most accurate for text intended for 6th graders and beyond.