JSFiddle - React, Tailwind, and code Playground
HTML
<span id="test">fffff</span>
<div>^-- What's the width of the overhang on the f?</div>
<div id="result">Calculated width: <span></span></div>
CSS
#test {
background:#ccc;
font-size:5em;
}
JavaScript
var width = $('#test').width();
$('#result span').text(width);