This weekend I needed to convert a DMG file to an ISO so I could burn a copy of the Mavericks installation to DVD from my PC. As the Mac desktop itself doesn’t provide any GUI to do so you have to use the Terminal for this. It’s easy enough, though to CLI-phobes need not panic.
Open a Terminal window and then change to the directory where your .DMG file is:
Then convert the file by doing:
hdiutil convert /pathto/yourDMG/originalfile.dmg -format UDTO -o /pathto/yourDMG/convertedfile.iso
This might take two or three minutes. Once it’s finished you may be given a file ending in .cdr