If you want to format an SD Card to FAT32, and you can only select FAT16 (among other choices) in Disk Utility, issue this command from the command line:
First find the name of your disk with “df”. The result is something like this:
iMac-van-Patrick:dev patricksinke$ df Filesystem 512-blocks Used Available Capacity iused ifree %iused Mounted on /dev/disk1 1951190584 1138759280 811919304 59% 142408908 101489913 58% / devfs 382 382 0 100% 662 0 100% /dev map -hosts 0 0 0 100% 0 0 100% /net map auto_home 0 0 0 100% 0 0 100% /home /dev/disk4s1 1983232 3072 1980160 1% 512 0 100% /Volumes/NAAMLOOS 1
The disk label is “NAAMLOOS 1”, so I know the filesystem name is /dev/disk4s1.
Then:
diskutil eraseVolume "MS-DOS FAT32" FAT32disk /dev/disk4s1
Where FAT32disk is the new label. You’re set and done.
