Let\'s say the rule is as follows:
.largeField { width: 65%; }
Is there a way to get \'65%\' back somehow, and not the pixel value?
There's no built-in way, I'm afraid. You can do something like this:
var width = ( 100 * parseFloat($('.largeField').css('width')) / parseFloat($('.largeField').parent().css('width')) ) + '%';