Macintosh HD Storage Window...?

[DrJames]

Hello,
I know I'm not the greatest at math, but does this make sense to anyone?
How would I go about fixing this?
I'm running OS X El Capitan Version 10.11.2 Beta.
I know I'm running a beta version of OS X but it's looked like this ever since I ran Yosemite.

 

[Weaselboy]

That readout gets its data from the Spotlight index and it is notoriously messed up the last couple OS version. If you reindex Spotlight with the below command in Terminal it will usually fix it (for a while).

sudo mdutil -E /