How do I fit an image (img) inside a div and keep the aspect ratio?

Question

I have a 48x48 div and inside it there is an img element, I want to fit it into the div without losing any part, in the mean time the ratio is kept, is it achievable using html and css?

Answer 1

You will need some JavaScript to prevent cropping if you don't know the dimension of the image at the time you're writing the css.

HTML & JavaScript

<div id="container">
    <img src="something.jpg" alt="" />
</div>

<script type="text/javascript">
(function() {

var img = document.getElementById('container').firstChild;
img.onload = function() {
    if(img.height > img.width) {
        img.height = '100%';
        img.width = 'auto';
    }
};

}());
</script>

CSS

#container {
   width: 48px;
   height: 48px;
}

#container img {
   width: 100%;
}

If you use a JavaScript Library you might want to take advantage of it.