Recover SD memory card real size
Why you are reading this and going to the point
Instead of reading or see a lot of steps to recover your memory card and probably you are trying to format with the windows format tool and you can't see any exFAT File System Option that is the default on the new sd cards, you will need to download a tool specific for sd cards.
you could have broken it when you format to create a boot device on your USB or when you play with the sizes of the memory card to create a funny USB that his size is 1 TB, for this, you normally Program the Microcontroller to report it as a 1TB file.
You can download the SD Card Formatter tool from https://www.sdcard.org/downloads/formatter/ This is a very easy tool to use since you only select the card that you want to format and click Format
A little of Explanation
The storage systems have been improving through the years in our computers. We are talking about the hard drive we use normally and the external storage units like a USB, we have differences in this in the specification of the storage for the number of writes and reads or the fastness of the device.
All these devices not only depends on the hardware they have but on the formatting or the archive system they are using, they need to be formatted to one of the most common formats like FAT32, NTFS, and ExFAT, on Linux we have other types like EXT(Extended FileSystem) the last version of this is Ext4 having some specific behaviors that help Linux systems look for files in a different way and reducing the fragmentation of the device than NTFS.
FAT32
This is the oldest file system that is currently still in use, this is been used since Windows 95, Initially was developed to replace FAT16 however this has been used on all windows computers so in the end has the best compatibility of all formats.
NTFS, a More recent file system
Is the Actual or more used file system created by Microsoft, NTFS help with the limitations of FAT32 like the size of the files that cannot be more than 4 gigs and the partitions that cannot be more than 8 Teras.
A unit with NTFS format has the possibility of file permissions and keeps a history of changes that can help us recover the hard drive if there is an issue and this can handle hard drive encryption giving an extra layer of security.
exFAT, File system for external devices
This is more recent however is with us since 2006 but nobody notices a lot since is been used for external storage(USB) principally, is a mix of FAT32 with NTFS giving us the security of NTFS and the lightness of FAT32. Was planned to be compatible with non-conventional devices like TVs, Mp3 players, Game consoles, etc...
