How to restore my external hard drive to full capacity after formatting it to MS-DOS?

Hello,

I had several external hard drives that worked perfectly in Windows, but they are only readable on my Mac (not editable). Therefore, I wanted to erase and reformat them to MS-DOS (FAT) so I can work (them) in both Windows and Mac OS. But, once I do this on my 8 TB Seagate, it is indicated that 6.6 TB out of the actual 8 TB is used (even though there is nothing in the hard drive). Moreover, I found this comment from Kappy (showed below) at the beginning of this year which I followed exactly, except that I set the format type to MS-DOS (FAT32). Nevertheless, 3/4 of the space in my external hard drive is filled with I do not know what (gosh space?, please anyone correct my ignorance).

Please, any one that knows any method to get full capacity of an external hard drive while keeping the MS-DOS format (like in my case) let me know!

Thank you in advance!!!!

KappyJan 20, 2018 3:11 PM in response to BAL-II

Level 10 (301,576 points)

Desktops

Jan 20, 2018 3:11 PM Re: How to reformat a usb drive to its full capacityin response to BAL-II

The formatted capacity of an advertised 256GB drive is around 240GBs. To partition and format the flash drive on your Mac is as follows:

Drive Partition and Format - El Capitan or Later

1. Open Disk Utility in the Utilities' folder.
2. After Disk Utility loads select the drive (out-dented entry with the mfgr.'s ID and size) from the side list.
3. Click on the Erase tab in the Disk Utility toolbar. A panel should drop down.
4. In the drop down panel set the partition scheme to GUID. Set the Format type to Mac OS Extended (Journaled.)
5. Click on the Apply button and click on the Done button when it is activated.
6. Quit Disk Utility.