Summing outerHeight of multiple divs
You'll have to add a class to the divs to be able to select them all

&lt;div id="div1" class="sumdiv"&gt;&lt;/div&gt;
&lt;div id="div2" class="sumdiv"&gt;&lt;/div&gt;


Then, use $.each() (http://api.jquery.com/each/)

var sum = 0;
$( ".sumdiv" ).each(function( index ) {
    sum += $(this).outerHeight()
});