Vertically and horizontally centering text in circle in CSS (like iphone notification badge)

Horizontal centering is easy: text-align: center;. Vertical centering of text inside an element can be done by setting line-height equal to the container height, but this has subtle differences between browsers. On small elements, like a notification badge, these are more pronounced.

Better is to set line-height equal to font-size (or slightly smaller) and use padding. You'll have to adjust your height to accomodate.

Here's a CSS-only, single <div> solution that looks pretty iPhone-like. They expand with content.

Demo: http://jsfiddle.net/ThinkingStiff/mLW47/

Output:

CSS:

.badge {
    background: radial-gradient( 5px -9px, circle, white 8%, red 26px );
    background-color: red;
    border: 2px solid white;
    border-radius: 12px; /* one half of ( (border * 2) + height + padding ) */
    box-shadow: 1px 1px 1px black;
    color: white;
    font: bold 15px/13px Helvetica, Verdana, Tahoma;
    height: 16px; 
    min-width: 14px;
    padding: 4px 3px 0 3px;
    text-align: center;
}

HTML:

<div class="badge">1</div>
<div class="badge">2</div>
<div class="badge">3</div>
<div class="badge">44</div>
<div class="badge">55</div>
<div class="badge">666</div>
<div class="badge">777</div>
<div class="badge">8888</div>
<div class="badge">9999</div>

Modern Solution

The result is that the circle never gets distorted and the text stays exactly in the middle of the circle - vertically and horizontally.

.circle {
  background: gold;
  width: 40px; 
  height: 40px;
  border-radius: 50%;
  display: flex; /* or inline-flex */
  align-items: center; 
  justify-content: center;
}

<div class="circle">text</div>

Simple and easy to use. Enjoy!

If you have content with height unknown but you know the height the of container. The following solution works extremely well.

HTML

<div class="center-test">
    <span></span><p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. 
    Nesciunt obcaecati maiores nulla praesentium amet explicabo ex iste asperiores 
    nisi porro sequi eaque rerum necessitatibus molestias architecto eum velit 
    recusandae ratione.</p>
</div>

CSS

.center-test { 
   width: 300px; 
   height: 300px; 
   text-align: 
   center; 
   background-color: #333; 
}
.center-test span { 
   height: 300px; 
   display: inline-block; 
   zoom: 1; 
   *display: inline; 
   vertical-align: middle; 
 }
.center-test p { 
   display: inline-block; 
   zoom: 1; 
   *display: inline; 
   vertical-align: middle; 
   color: #fff; 
 }

EXAMPLE http://jsfiddle.net/thenewconfection/eYtVN/

One gotcha for newby's to display: inline-block; [span] and [p] have no html white space so that the span then doesn't take up any space. Also I've added in the CSS hack for display inline-block for IE. Hope this helps someone!