Readability Formulas
Formulas Used for:
English Web Page Analysis
Forcast Grade Level = 20 - (# of one-syllable words out of 150 words / 10)
Forcast is designed to include content that is not in sentence form, i.e. images, links, lists, forms, etc.
The Forcast Grade Level score translates into a numerical grade, e.g. a score of 9.8 is equivalent to 9th grade reading level in the United States.
How is the Forcast score calculated?
English Text Analysis
Flesch-Kincaid Grade Level = (0.39 * ASL) + (11.8 * ASW) -15.59
Flesch Reading Ease = 206.835- (84.6 * ASW) - (1.015 * ASL)
ASW: Average number of syllables per word (in a 100-word chunk of text)
ASL: Average sentence length (number of words per sentence)
The Flesch-Kincaid Grade Level score translates into a numerical grade, e.g. a score of 6.8 is equivalent to 6th grade reading level in the United States.
Flesch Reading Ease scores range from 0 to 100, with 0 as the most difficult and 100 as the least difficult to read. A score below 30 is considered very difficult, while a score of 70 is considered appropriate for adult readers.
How are the Flesch-Kincaid and Flesch Reading Ease scores calculated?
Spanish Web Page and Text Analysis
Huerta Reading Ease = 206.84 - (0.60 * P) - (1.02 * F)
P = Number of syllables per 100 words
F = Number of sentences per 100 words
Huerta Reading Ease scores range from 0 to 100, with 0 as the most difficult and 100 as the least difficult to read. A score below 30 is considered very difficult, while a score of 70 is considered appropriate for adult readers.
How is the Huerta Reading Ease score calculated?
Japanese Web Page and Text Analysis
For Japanese, the critical factors are: sentence length, length of runs of Roman letters and symbols and of the different Japanese characters, and the ratio of tooten to kuten.
The formula used (from Hayashi 1992) for analyzing your content is:
Readability Score = -(0.12 * LS) - (1.37 * LA) + (7.4 * LH) - (23.18 * LC) - (5.4 * LK) - (4.67 * CP) + 115.79
LS = length of the sentences
LA = average number of Roman letters and symbols per run
LH = average number of Hiragana characters per run
LC = average number of Kanji character per run
LK = average number of Katakana character per run
CP = ratio of tooten (comma) to kuten (period)
Run = a continuous string of the same type of character