Vertical align text in block element

According to the CSS Flexible Box Layout Module, you can declare the a element as a flex container (see figure) and use align-items to vertically align text along the cross axis (which is perpendicular to the main axis).

All you need to do is:

display: flex;
align-items: center;

See this fiddle.

You can also try

a {
  height:100px;
  line-height:100px;
}

li a {
width: 300px;
height: 100px;
display: table-cell;
vertical-align: middle;
margin: auto 0;
background: red;

}

You can try the display:inline-block and :after.Like this:

HTML

<ul>
    <li><a href="">I would like this text centered vertically</a></li>
</ul>

CSS

li a {
    width: 300px;
    height: 100px;
    margin: auto 0;
    display: inline-block;
    vertical-align: middle;
    background: red;  
}
li a:after {
  content:"";
  display: inline-block;
  width: 1px solid transparent;
  height: 100%;
  vertical-align: middle;
}

Please view the demo.