height form the top to the element
window.addEventListener('load', function() {
//get the element
var elem = document.getElementById('test');
//get the distance scrolled on body (by default can be changed)
var distanceScrolled = document.body.scrollTop;
//create viewport offset object
var elemRect = elem.getBoundingClientRect();
//get the offset from the element to the viewport
var elemViewportOffset = elemRect.top;
//add them together
var totalOffset = distanceScrolled + elemViewportOffset;
//log it, (look at the top of this example snippet)
document.getElementById('log').innerHTML = totalOffset;
});