Hard Disk Manager showes I have 18 EB of disk in use. That is Exabytes, not a typo.

Hard Disk Manager shows I have 18 Exabytes of disk in use on my Macintosh HD. That is 1,000 x 1,000 x TB.
Additionally both size and free are 410 GB.

Mac version 1.3.873 current as of this date.