JSFiddle - React, Tailwind, and code Playground

HTML

<div id="outerHeight"></div>
<div id="outerWidth"></div>
<div id="calc"></div>

JavaScript

$(document).ready(function(){
    $('#outerHeight').html('Height of non-element is: '+ $('notAnElement').outerHeight());
    
    $('#outerWidth').html('Width of non-element is: '+ $('notAnElement').outerWidth());
    
    $('#calc').html('Document height is: '+ ($(document).outerHeight() + $('notAnElement').outerHeight()));
});