title: How to calculate available device storage?
body: <p>I'm using <strong>OSMDroid</strong> and trying to figure how much space I have on a device for offline tile storage.
  The device is a <strong>Samsung SM-T530NU</strong>. It shows the following information:</p>
  
  <pre><code>Storage
  
  Total space
  Total device capacity
  16.000GB
  
  Owner
  System memory
  The minimum amount of storage space required to run the system.
  4.05GB
  
  Used space
  The amount of storage space currently being used.
  7.86GB
  
  Cached data
  0.93GB
  
  Miscellaneous files
  The amount of memory used to store miscellaneous files.
  1.81GB
  
  Other users
  John Doe
  121MB
  
  Available space
  The amount of storage space currently available
  1.35GB
  </code></pre>
  
  <p>So if I calculate the total amount not used:</p>
  
  <p>16GB - (7.86GB + 0.93GB + 1.81GB + .121GB) = 
  16GB - 10.721 = 
  5.279GB</p>
  
  <p>Yet the available space is listed as 1.35GB.
  Where is the other 3.929GB?</p>