JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrap">
    <div class="child"></div>
</div>

CSS

.wrap{
    width:300px;
    height:400px;
    border:1px solid red;
}

.child{
    width: calc(20% + 90px);
    min-width: calc(20% + 90px);
    border:1px solid blue;
}

JavaScript

var cw = $('.child').width();
var cmw = $('.child').css('min-width');
$('.child').text(cw + " " + cmw);
$('.child').css({
    'height': cw + 'px'
});