Apple - Weird free spaces estimation
This information is calculated based on the Spotlight index. If your index is incorrect, this information can be incorrect too. Try reindexing your disk:
sudo mdutil -E /
sudo elevates the command to root to allow full control on the system. mdutil is the tool for controlling Spotlight. -E is the reindex option and / specifies the path to reindex. For more information on mdutil, see the man page.
It's possible that you have a corrupt index. The steps I'm going to show come from this Apple Support page. You must have permissions to add and remove items from the Privacy tab.
- Click
Apple menu > System Preferences > Spotlight - Click the Privacy tab
- Drag the folder or disk that you want to index again to the list of locations that Spotlight is prevented from searching or click the Add (+) button to add it to the list. If the list is empty, add your main SSD, most commonly named
Macintosh HD. - Click OK to confirm
- Select the folder or disk you just added, then click the Remove (–) button to remove it from the list.
- Quit System Preferences. Spotlight will reindex the contents of the folder or disk.
Once you've done all this, restart your Mac and check About This Mac -> Storage again. If the storage displays the same, then you know it's not because of a corrupt index.