Horizontally center a div in a div How can I horizontally center a div within a div using CSS (if it's even possible)? The outer div has width:100%: <div id="outer" style="width:100%"> <div id="inner">Foo foo</div> </div> Answer : You can apply this CSS to the inner div: #inner { width: 50%; margin: 0 auto; } Of course, you don't have to set the width to 50%. Any width less than the containing div will work. The margin: 0 auto is what does the actual centering. If you are targeting IE8+, it might be