Google Docs Example

HTML

<iframe src="https://docs.google.com/forms/d/1qy1A6vIpf-l2G-ryjh8Rm1iSBPBskATsWK3XJuc_h34/viewform?embedded=true" width="760" frameborder="0" marginheight="0" marginwidth="0">
Loading...
</iframe>

JavaScript

$('iframe').load(function() {
    this.style.height =
    this.contentWindow.document.body.offsetHeight + 'px';
    
    console.log(99);
});