JSFiddle - React, Tailwind, and code Playground

HTML

<div id="before">BEFORE</div>
<div id="after">AFTER</div>

<div id="msg">/div>

CSS

#before, #after{
height: 100px;
width: 200px;
border: 2px solid red;   
}

#after{
 transform:scale(.5);
-ms-transform:scale(.5);
-moz-transform:scale(.5);
-webkit-transform:scale(.5);
-o-transform:scale(.5);  
}

JavaScript

$('#msg').html('before:'
                + $('#before').outerHeight()
                +'<br /> after:'
                +$('#after').outerHeight()
               );