Height proportional to width using jQuery
sos https://stackoverflow.com/a/22973675
HTML
<div id="my_proportional_div"></div>
CSS
#my_proportional_div {
background: grey;
width: 100%;
}
JavaScript 1.7
$(window).ready(function () {
var ratio = 3 / 10, $div = $('#my_proportional_div');
$div.height($div.width() * ratio);
$(window).bind('resize', function() { $div.height($div.width() * ratio); });
});