How to make an empty div take space

it works if you remove floating. http://jsbin.com/izoca/2/edit

with floats it only works if theres some content e.g.  

Try adding   to the empty items.

I don't understand why you're not using a <table> here, though? They will do this kind of stuff automatically.

Slight update to @no1cobla answer. This hides the period. This solution works in IE8+.

.class:after
{
    content: '.';
    visibility: hidden;
}