A script extending MyAnimeList.net for displaying average duration per episode and average number of episodes per entry.

[MyAnimeList] Average-Duration&Average-Episode.js

// ==UserScript==
// @name         [MyAnimeList] Average-Duration&Average-Episode
// @namespace    http://tampermonkey.net/
// @version      1.2
// @description  A script for extending MyAnimeList.net for displaying average duration per episode and average number of episodes per entry.
// @author       xamantra
// @updateURL    https://gist.githubusercontent.com/xamantra/e3dd9b11909a0375103af150d9bbe0e5/raw/dd0a389d1f0d2b84576688045dfdbe71a2a7684c/%255BMyAnimeList%255D%2520Average-Duration&Average-Episode.js
// @downloadURL  https://gist.githubusercontent.com/xamantra/e3dd9b11909a0375103af150d9bbe0e5/raw/dd0a389d1f0d2b84576688045dfdbe71a2a7684c/%255BMyAnimeList%255D%2520Average-Duration&Average-Episode.js
// @supportURL   https://gist.github.com/xamantra/e3dd9b11909a0375103af150d9bbe0e5
// @match        https://myanimelist.net/profile/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    var js = "var inserted = false;\r\n\r\nfunction appendMinsPerEpisode() {\r\n  var daysRaw = $(`div.stats.anime > div.stat-score.di-t.w100.pt8 > div.di-tc.al.pl8.fs12.fw-b`).text();\r\n  var episodesRaw = $(`div.stats.anime > div.mt12.ml8.mr8.clearfix > ul.stats-data.fl-r > li:nth-child(3) > span.di-ib.fl-r`).text();\r\n  var totalRaw = $(`div.stats.anime > div.mt12.ml8.mr8.clearfix > ul.stats-data.fl-r > li:nth-child(1) > span.di-ib.fl-r`).text();\r\n  var ptwRaw = $(`div.stats.anime > div.mt12.ml8.mr8.clearfix > ul.stats-status.fl-l > li:nth-child(5) > span`).text();\r\n  if (daysRaw === null || daysRaw === undefined) {\r\n    return;\r\n  }\r\n  if (episodesRaw === null || episodesRaw === undefined) {\r\n    return;\r\n  }\r\n  var days = Number(daysRaw.replace(`Days: `, ``).split(`,`).join(``));\r\n  var episodes = Number(episodesRaw.split(`,`).join(``));\r\n  var total = Number(totalRaw.split(`,`).join(``));\r\n  var ptw = Number(ptwRaw.split(`,`).join(``));\r\n  var avgEpisodes = Math.round(episodes \/ (total - ptw));\r\n  console.log({ days, avgEpisodes });\r\n  var avg = Math.round((days \/ episodes) * 1440);\r\n  var element = `<div class=\"stat-score di-t w100 pt8\">\r\n      <div class=\"di-tc al pl8 fs12 fw-b\"><span class=\"fn-grey2 fw-n\">Minutes\/ep: <\/span>${avg}<\/div>\r\n      <div class=\"di-tc ar pr8 fs12 fw-b\">\r\n        <span class=\"fn-grey2 fw-n\">Episodes\/entry:<\/span>\r\n        <span class=\"score-label score-0\">${avgEpisodes}<\/span>\r\n      <\/div>\r\n    <\/div>`\r\n  $(element).insertBefore(`#statistics > div:nth-child(2) > div.stats.anime > div.stats-graph.mt8`);\r\n  inserted = true;\r\n}\r\n\r\nasync function sleep(timeout = 1000) {\r\n  return new Promise((resolve, _) => {\r\n    setTimeout(() => {\r\n      resolve();\r\n    }, timeout);\r\n  });\r\n}\r\n\r\nasync function run() {\r\n  while (!inserted) {\r\n    await sleep(1000);\r\n    console.log(\'Inserting avg. mins per episode element...\');\r\n    appendMinsPerEpisode();\r\n  }\r\n}\r\n\r\nrun();";

    var scriptTag = document.createElement("script");
    scriptTag.innerHTML = js;
    document.head.appendChild(scriptTag);
})();