JSFiddle - React, Tailwind, and code Playground
HTML
<div id="container" class="main-class"></div>
CSS
.main-class {
border: 1px solid gray;
width: 500px;
height: 100px;
padding: 10px;
}
JavaScript
$(document).ready(function() {
var outerWidth = $("#container").outerWidth();
var outerHeight = $("#container").outerHeight();
alert(`${outerWidth} x ${outerHeight}`);
});