title: calculating pixel size from ppi
body: <p>I need some help to verify that i have made my calculations correct.</p>
  
  <p>I want to determine number of pixels in the span of 13.6 millimeters for a specific device that is 224,17 pixels per inch.</p>
  
  <p>( if 1 inch = 224.17ppi therefor: 1 centimeter = 569.39ppcm therefor: 1 millimeter = 5.69 ppmm )</p>
  
  <p><strong>I calculate 13.6mm = 77.35 pixels</strong> </p>