title: Get the height of an element minus padding, margin, border widths
body: <p>Does anyone know if it's possible to get just the height of an element (minus vertical padding, border, and margin) when there is no inline height declaration? I need to support IE8 and above.</p>
  
  <p><code>el.style.height</code> doesn't work because the styles are set in an external style sheet.</p>
  
  <p><code>el.offsetHeight</code> or <code>el.clientHeight</code> doesn't work because they include more than just the element's height. And I can't just subtract the element's padding, etc. because those values are also set in a CSS stylesheet, and not inline (and so <code>el.style.paddingTop</code> doesn't work).</p>
  
  <p>Also can't do <code>window.getComputedStyle(el)</code> because IE8 doesn't support this.</p>
  
  <p>jQuery has the height() method, which offers this, but I'm not using jQuery in this project, plus I just want to know how to do this in pure JavaScript.</p>
  
  <p>Anyone have any thoughts? Much appreciated.</p>