SSD not showing real size

From my system. The main drive is 256GBs. The above show three different views that can be displayed if you use the View gadget in Disk Utility's toolbar.

There is nothing different except for my 256GB drive and your 1TB drive. Formatted sizes will be different because of the sizes involved.

Again, there is nothing wrong with your system.

That is the correct formatted size. Partition Drives & Create APFS 'Containers' for Space Sharing with Disk Utility, Drives & Create APFS 'Containers' for Space Sharing with Disk Utility, Disks, partitions, volumes, containers.

Get Correct Storage Information

Do not use the information from the Storage section of the About This Mac dialog. Ignore the Storage information as it is typically wrong. To find out the correct information for any disk: Select a Desktop disk icon. Press Command-I to open the Get Info window and look at the topmost panel displayed. You will find the disk information displayed for Capacity, Available, and Used. If you have more than one disk/partition then repeat for each one on your Desktop.

The categories found in the Storage section of About This Mac is simply an arbitrary way of displaying files on your drive. There are no such categories actually on the drive.

Well, then that’s the cause of your problem. Only Boot Camp Assistant should be used.

Your best fix would be to clone to an external drive, then erase and reformat your internal drive as one partition, then clone your external drive back to your internal drive.

Well, it's too late now. Should have tried to resolve the issue with Boot Camp Assistant, as it is the only way to add or remove boot camp partitions correctly.

Previous advice stands, you're going to have reformat your internal drive to get the space back. The best way to do that it to backup the drove to an external with cloning software.

Are you running Time Machine? Someone correct me if I'm wrong but it could be local backups/snapshots. You can disable these in terminal using the command sudo tmutil disablelocal - See if this has made a difference, if not, you can re-enable them using sudo tmutil enablelocal . Worth a shot.

If you see no change, it wouldn't hurt taking Kappy's advice, he's a very knowledgable person on these subjects.

Hi,

I have been reading over this thread and noticing a lot of what could've been done and what went wrong. I don't think anyone has that answer but I have noticed a pattern that you would need to call Apple Support about this but a handful of Mac's running Sierra, High Sierra or Mojave have all encountered this issue and it has nothing to do with the way you formatted the computer, or a hardware issue. Let's get that out of the way for now.

What this issue is a communication issue between the OS and the the Drive currently being used, if it is accessing iCloud that has a major role as for some reason iCloud has been communicating with the computer incorrectly and as far as I last knew, Apple was looking for a fix to that as soon as possible and I don't believe they have found it yet. I would strongly recommend you contact Apple Support and get a Senior Advisor onto the case in order to help you fix the issue and possibly corrupted files or worse causing the incorrect readings.

You are using APFS, not HFS+. Size change is due to the format change. Don't fret it.

I hope that you used the Boot Camp Assistant to remove your Boot Camp partition and that you didn't use Disk Utility for that purpose.

Hello,

I've put in a call for someone who is really good at Bootcamp and partitioning issues.