JavaScript Ninja – Element’s Measurements

(function(w){
return { 'width':{ 
           'value':  Number(w.width.toLowerCase().replace(/[^\d\.]/g,""))
         , 'unit':   w.width.replace(/[\d\.]/g,"")
         }
        ,'height':{ 
           'value':  Number(w.height.toLowerCase().replace(/[^\d\.]/g,""))
         , 'unit':   w.height.replace(/[\d\.]/g,"")
         }
        }
}(
window.getComputedStyle(document.querySelector('html'))
));

get something like this:

{
  width: {
    value: 1092.8
    , unit: "px"
  }
  , height: {
    value: 215.2
    , unit: "px"
  }
}