 <pre><code>$('select').change(function(){ var sum = 0; $('select :selected').each(function() { sum += Number($(this).val()); }); $("#sum").html(sum); }); </code></pre> <p><a href="http://jsfiddle.net/8mnQR/1/">http://jsfiddle.net/8mnQR/1/</a></p>