How to convert DMG to ISO and ISO to DMG on macOS
Updated 2020-04-04 · Published 2009-11-03

The hdiutil utility is used to manipulate disk images. This includes creating disk images, mounting and unmounting disk images, and burning a disk image, it can also be used to convert different image types. In order to convert a DMG image to an ISO disk image, run the following command from the terminal. Be sure to change Filename to the correct file name. The command right below that removes the added '.cdr' that the utility automatically appends.
Convert DMG to ISO
hdiutil convert Filename.dmg -format UDTO -o Filename.iso
mv Filename.iso.cdr Filename.iso
Convert ISO to DMG
If you need to convert ISO disk images to a DMG image, run the following command from the terminal.
hdiutil convert Filename.iso -format UDRW -o Filename.dmg