Aspect Ratio Calculator

aspect_ratio_calculator.html

<script type="text/javascript">
    window.addEventListener("resize", aspectRatio);
    function aspectRatio() {
        var w = window.innerWidth;
        var h = window.innerHeight;
        var r = w/10;
        var aspect = document.querySelector('pre');
        var rounded = Math.round( h/r * 10 ) / 10;
        aspect.innerHTML = "<pre style='position:fixed; top: 30px; right: 30px; color: #fff; background: #000; padding: 10px 20px; z-index: 99999999;'>"+ w/r +":"+ rounded +"</pre>";
    }
</script>
<pre></pre>