Escala de elementos proporcionalmente utilizando CSS y JQuery3
$('.box').css('transform','scale(.6)');
console.log($('.box').width())
SAMER SAEID
$('.box').css('transform','scale(.6)');
console.log($('.box').width())<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class='box'></div>.box{
width:100px;
height:100px;
background:#000;
}let scale = .6;
let w = $('.box').width() * scale;
let h = $('.box').height() * scale;
$('.box').css({'height' : h, 'width' : w})
console.log($('.box').width())