reading-time.js

(function($) {
    /*!
    A very simplified version of:

    Name: Reading Time
    Dependencies: jQuery
    Author: Michael Lynch
    Author URL: http://michaelynch.com
    Date Created: August 14, 2013
    Date Updated: January 24, 2014
    Licensed under the MIT license

    */
    $.fn.readingTime = function(selector) {

        //return if no element was bound
        //so chained events can continue
        if(!this.length) { 
            return this; 
        }

        //define element
        var el = $(this);

        // words per minute
        var wpm = 270;

        // calculate the reading time
        var reading_time = Math.round(el.text().split(' ').length / wpm);

        // don't display anything if reading time is less that 30 secs
        if (reading_time < 1)
            return this;
        else
            $(selector).html(reading_time + ' min. read &ndash; ');
    }
})(jQuery);