title: Calculate Mp3 duration based on bitrate and file size
body: <p>I try to calculate mp3 duration by using bitrate and file size , after some search i found this formula: </p>
  
  <p><code>(mp3sizeInByte*0.008)/bitrate</code></p>
  
  <p>i am using <code>mp3sizeInByte*0.008</code> to convert byte to Kbits.</p>
  
  <p>but its not so accurate , in result there is couple second different compare to actual mp3 duration.</p>
  
  <p>i want know this right formula ? </p>