JSFiddle - React, Tailwind, and code Playground

HTML

<div id="screenSize"/>

JavaScript

function getScreenSizeInches() {    
    var $temp =  $('<div style="overflow:hidden;visibility:hidden;width:10in"/>').appendTo('body'),
       dpi = $temp[0].offsetWidth / 10;
    return screen.width / dpi + 'x' + screen.height / dpi;
}

$('#screenSize').text(getScreenSizeInches());