JSFiddle - React, Tailwind, and code Playground

HTML

<div id="test"></div>

CSS

#test {
    width: 200px;
    height: 150px;
    margin-top: 100px;
    margin-left: 250px;
    padding: 50px;
    background: gray;
    font-size: 120%;
}

JavaScript

var test = document.getElementById("test"),
    rect = test.getBoundingClientRect();

var str = "";
for (i in rect) {
    str += i + " = " + rect[i] + "<br>";
}
test.innerHTML = str;