Formula to detect the ease of reading a text according to Flesch Reading Ease.

See syllable for detecting syllables.

npm:

$ npm install flesch

Component:

$ component install wooorm/flesch

Bower:

$ bower install flesch

var flesch = require('flesch');

/**
 * For “The cat sat on the mat” (1 sentence, 6 words,
 * 6 syllables).
 */

flesch({
    'sentence' : 1,
    'word' : 6,
    'syllable' : 6
});
// 116.14500000000001

/**
 * For “The Australian platypus is seemingly a hybrid of 
 * mammal and reptilian creature.” (1 sentence, 13 words,
 * 26 syllables).
 */

flesch({
    'sentence' : 1,
    'word' : 13,
    'syllable' : 26
});
// 24.440000000000026

Given an object containing the number of words (word), the number of sentences (sentence), and the number of syllables (syllable) in a document, returns the reading ease associated with the document.

Returned values are 120 (every sentence consisting of only two one-syllable words), or lower (including negative values).

The values have the following semantics:

• automated-readability — Uses character count instead of an error-prone syllable parser;
• coleman-liau — Uses letter count instead of an error-prone syllable parser;
• dale-chall-formula — Uses a dictionary; suited for higher reading levels;
• flesch-kincaid — Like flesch-formula; returns U.S. grade levels;
• gunning-fog — Uses syllable count; hard to implement with a computer (needs POS-tagging and Named Entity Recognition);
• smog-formula — Like gunning-fog-index; without the need for advanced NLP tasks;
• spache-formula — Uses a dictionary; suited for lower reading levels.

MIT © Titus Wormer