používej radši powershell to je taky konzole a umí toho víc
https://www.sharepointsky.com/check-file-size-using-powershell/
https://social.technet.microsoft.com/Forums/lync/en-US/e613af97-07bd-4c13-a9a3-4da811d608d4/how-to-determine-the-file-size-using-powershell-script?forum=ITCG