title: Actual physical length vs points/pixels on excel worksheet
body: <p>After reading countless pages of information on the insanely confusing aspect of excel graphics, I feel I have no choice but to ask for help.  My details are as follows:</p>
  
  <p>Applicable system parameters:</p>
  
  <ul>
  <li>Windows 7 - 64 bit</li>
  <li>Screen res:  1280 x 720, 96 DPI</li>
  <li>Office 10 - 64 bit</li>
  </ul>
  
  <p>Aside from checking configuration in the windows settings, I pulled these values also using API calls.</p>
  
  <p>When I remove all the items from my excel window (ie. scroll bars, etc), application.usablewidth returns 960.  Zoom is constantly at 100%, although this does not change the aforementioned value.</p>
  
  <p>From what I understand, given my DPI settings, 72 points is equivalent to 96 pixels and that should equal to 1 inch, or 2.54 cm.</p>
  
  <p>However, when I draw a line on to the excel spreadsheet (ie. activesheet.shapes.addline(100,100,172,100)), and I use a ruler to measure the length of the line on the screen, it is actually longer by a factor of 1.75x.</p>
  
  <p>Although it is very easy to code in a ratio which would provide an appropriate calibration, I'd like to understand why is it the case?  What am I missing/omitting?</p>
  
  <p>Thank you in advance for any suggestions.</p>