Vertically centering a div inside another div

Question

I want to center a div which is added inside another div.

<div id="outerDiv">
    <div id="innerDiv">
    </div>
</div>

This is the CSS I am currently using.

    #outerDiv{
        width: 500px;
        height: 500px;
        position:relative;
    }

    #innerDiv{
        width: 284px;
        height: 290px;
        position:absolute;
        top: 50%;
        left:50%;
        margin-top: -147px;
        margin-left: -144px;
    }

As you can see,the approach I use now depends on values for width and height of innerDiv.If the width/height changes, I will have to modify the margin-top and margin-left values.Is there any generic solution that I can use to center the innerDiv always irrespective of its size?

I figured out that using margin:auto can horizontally allign the innerDiv to the middle.But what about vertical allign middle?

Answer 1

Vertically centering a div inside another div

#outerDiv{
  width: 500px;
  height: 500px;
  position:relative;
  
  background-color: lightgrey;  
}

#innerDiv{
  width: 284px;
  height: 290px;
  
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%); /* IE 9 */
  -webkit-transform: translate(-50%, -50%); /* Chrome, Safari, Opera */	
  
  background-color: grey;
}

<div id="outerDiv">
  <div id="innerDiv"></div>
</div>

Answer 2

try to align inner element like this:

top: 0;
bottom: 0;
margin: auto;
display: table;

and of course:

position: absolute;

Answer 3

When your height is not set (auto); you can give inner div some padding (top and bottom) to make it vertically center:

<div>
    <div style="padding-top:20px;padding-bottom:20px">
    <!--content-->
    </div>
</div>

Answer 4

If you still didn't understand after reading the marvellous answers given above.

Here are two simple examples of how you can achieve it.

Using display: table-cell

.wrapper {
  display: table-cell;
  vertical-align: middle;
  text-align: center;
  width: 400px;
  height: 300px;
  border: 1px solid #555;
}

.container {
  display: inline-block;
  text-align: left;
  padding: 20px;
  border: 1px solid #cd0000;
}

<div class="wrapper">
  <div class="container">
    Center align a div using "<strong>display: table-cell</strong>"
  </div>
</div>

Using flex-box (display: flex)

.wrapper {
  display: flex;
  justify-content: center;
  width: 400px;
  height: 300px;
  border: 1px solid #555;
}

.container {
  align-self: center;
  padding: 20px;
  border: 1px solid #cd0000;
}

<div class="wrapper">
    <div class="container">
        Centering a div using "<strong>display: flex</strong>"
    </div>
</div>

Note: Check the browser compatibility of display: table-cell and flex before using the above mentioned implementations.

Answer 5

I know that question was created year ago... Anyway thanks CSS3 you can easily vertically aligns div in div (example there http://jsfiddle.net/mcSfe/98/)

<div style="width: 100px; height: 100px">
<div>
Go to Hell!
</div>
</div>

div
{
display:-moz-box;
-moz-box-align:center;
}