html - How to center div that contains an image within a div?

Question

I need to center a image inside a div both vertically and horizontally. I am using the display inline-block property.

HTML

<div class="container">
   <div class="box">
     <div class="image-container"><img src="image.gif"></div>
   </div>
</div>

CSS

.box {
    display: inline-block;
    width: 32px;
    height: 32px;
    border: 1px solid #f2f2f2;
    margin-left: 1px;
    margin-top: 5px;
}

Answer 1

This approach works perfectly for dynamic content of unknown dimensions.

jsFiddle example

Basically, we are using vertical-align:middle for vertical centering, and text-align:center for horizontal centering. In order for vertical-align:middle to work on a div, we need to set the parent elements to display:table, and the targeted child div to display:table-cell. Sure you could achieve such centering with absolute positoning, however, that would require you to know the dimensions of the img. This approach works for unknown dimensions.

HTML

<div class="container">
   <div class="box">
       <img src="http://placehold.it/200x200">
   </div>
</div>

CSS

html, body {
    height:100%;
    width:100%;
    margin:0px;
}
.container {
    display:table;
    vertical-align:middle;
    text-align:center;
    height:100%;
    width:100%;
}
.box {
    display:table-cell;
    vertical-align:middle;
}