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Convert DVD to ISO on Mac

with 35 comments

Another faculty member asked me how to convert a DVD to an ISO on his Mac. Here are the instructions for everybody.

He needed to convert it because he wanted to deploy it on a Netbook from a USB drive. We all know you shouldn’t do this unless you’ve paid for the license and are only installing it on a single machine, like the Adobe license specifies.

The only tricky part to this is the last command-line step, which I borrowed from Mac OS X hints.

1. Open Disk Utility on your Mac OS X. It’ll look something like this:


2. Click the New Image icon in the tool bar, and save it as a compressed file. This writes it as a .dmg file, which is an Apple format .iso file.


It’ll take a while to write. The length of time is relevant to the size of the image on the DVD.


3. This is the first of two tricky steps. They’re tricky because you need to use the command-line. If you followed the instructions, you’ve saved the .dmg file on the Desktop. Now, you need to convert the .dmg formatted file to an .iso formatted file. You open Terminal, which is found in your Applications folder. Once launched follow the steps below. Change the directory to the Desktop or the folder where you put the file. You must do this before running this command because I’ve used relative file syntax (more or less only the file name). Alternatively, you could provide fully qualified file names.

MacPro:~ mclaughlinm$ cd Desktop
MacPro:Desktop mclaughlinm$ ls *.dmg
MacPro:Desktop mclaughlinm$ hdiutil convert Acrobat9.dmg -format UDTO -o Acrobat9.iso
Reading Acrobat9                         (Apple_ISO : 0)…
Elapsed Time: 27.655s
Speed: 22.2Mbytes/sec
Savings: 0.0%
created: /Users/mclaughlinm/Desktop/Acrobat9.iso.cdr

4. Before you copy it to your Windows USB, you need to remove the trailing .cdr from the file name. The syntax at the command-line is:

MacPro:Desktop mclaughlin$ mv Acrobat9.iso.cdr Acrobat9.iso

5. Open Finder, and copy the .iso to your USB drive, and delete the temporary copy.

Hope this helps some folks.

Written by maclochlainn

September 3rd, 2009 at 10:03 pm

35 Responses to 'Convert DVD to ISO on Mac'

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  1. “You open Terminal, and change the directory to the Desktop or where you put the file. You must do this before running this command because I’ve used relative file syntax. ”

    thanks for trying to help us non tech types but that last line might have well been in japanese. anyone who needs to look up how to do these things will probably need it explained. we are mac users for god sake! 😉


    27 Jul 10 at 1:11 pm

  2. I’ve updated it. Hopefully, that helps fill any gap. The problem is users can put the file in any folder and the syntax for folders with white spaces is more complex.


    27 Jul 10 at 4:13 pm

  3. I’m horrified to read Henry’s comment. I’m a mac user which is – as you might know – UNIX. This indeed why it was called Mac OS X rather than simply Mac OS 10.

    I would rather expect such a comment from a GUI-only user.



    21 Oct 10 at 1:57 pm

  4. Thank you very much from Japan!


    4 Dec 10 at 8:27 pm

  5. If you drag the .dmg icon from the finder into terminal it will enter the fully qualified name for you. That makes this even easier.


    4 Mar 11 at 11:41 am

  6. Great instructions. Too bad the ISO conversion wasn’t just built into Disk Utility. It’s nice to know that there’s a command line workaround and no need to hunt for additional software. Thanks for sharing!


    26 Mar 11 at 4:20 pm

  7. Excellent advice. Thanks V Much


    30 May 11 at 11:12 am

  8. In Lion, I notice that one of the options under “Image Format” is “CD/DVD Master”. This sounds like an ISO to me, although the output file is simply .cdr.

    I am going to give this a try, renaming it to .iso after the extract completes. I will let you know if this seems to work.

    I am using it to create a Windows 7 Boot disk for installing Win7 under BootCamp. BC4 wants an ISO to do this.

    And why do I want to use BC in the first place?

    Unfortunately, some critical software of which I have just purchased a Mac version does not work on Lion and, as this is a new-hardware Mac Mini, I can’t go backwards to Snow Leopard. Fortunately, I do have a Windows equivalent that *should* work under BootCamp / Win7. (MediaShout – for anyone who is interested).

    Paul (Aussie)

    29 Jul 11 at 10:48 pm

  9. Yep – seems to be correct. Renamed the .cdr file to .iso and pointed Boot Camp Assistant at it, and it just got busy doing things.

    Seems that someone at Apple was listening…

    Paul (Aussie)

    29 Jul 11 at 10:55 pm

  10. Awesome find. Thanks for the update.


    29 Jul 11 at 11:29 pm

  11. It does the same under Snow Leopard too! i.e. what Paul (Aussie) says in both of his posts.

    Thx heaps to you all!

    SO you no longer need the “Tricky steps”

    Andrew (Aussie)

    17 Nov 11 at 6:30 pm

  12. Thanks a lot. I don’t know what I did…but I did it!

    Is it correct that the dmg file is smaller than the iso file (3.62 GB -> 3.92 GB)?

    Francesco (from Switzerland)

    16 Jan 12 at 12:07 pm

  13. If you have no problem reading the file, then it’s fine. It’s possible that you’re looking at a measurement where 1,024 is measured as 1,000 versus on the CD it’s measured against the 1,024.


    16 Jan 12 at 10:30 pm

  14. Thanks to all.
    I converted to iso but I cant delete ei.cfg . any suggestion please .


    17 Jun 12 at 1:35 am

  15. thanks !


    6 Jul 12 at 10:06 am

  16. Thank you very much. It was very helpful 🙂


    23 Aug 12 at 7:33 pm

  17. This worked beautifully on ML. Thanks so much!!


    23 Nov 12 at 8:46 pm

  18. Thank you very much, I appreciate you are the best.


    6 Dec 12 at 5:39 pm

  19. Very good posting, first in Google and solves the problem!!!

    Thank you very much.


    22 Dec 12 at 2:18 am

  20. thank you so much from HK


    6 Jan 13 at 10:19 pm

  21. it’s working very well.
    thank you very much from korea.


    26 Apr 13 at 12:38 am

  22. You can actually drag and drop the file to the terminal and it will automatically generate the path to it. That way you can save a step.


    12 May 13 at 3:51 pm

  23. hi!

    I’ve tried this to convert an installationCD/DVD for Snow Leopard on a Mac with Lion (to put it on a USBstick and install on an older computer that doesn’t have the CDcompartment working), but meet a problem when I come to the step where you convert the .dmg file to an .iso in Terminal.

    when I write hdiutil convert and the file name, Terminal answers “hdiutil: convert: only single input file can be specified”

    Does this mean there are too many different files on the CD/DVD that I’m trying to convert?

    I don’t seem to be able to find the install file on the CD/DVD with Terminal and single it out to convert only that, and I also wonder if I don’t need the other files to install Snow Leopard …

    grateful for answers…!


    4 Nov 13 at 8:34 am

  24. Tove, Can you provide the syntax you’re using?


    11 Nov 13 at 2:00 am

  25. @Paul (Aussie)
    I’m trying the same thing as you for the same reasons.
    But I got only a input/output error
    Is the cd maybe broken?
    Otherwise I would be happy to have finally Windows back on my Mac (just for gaming)


    3 Jan 14 at 4:09 pm

  26. Micha, Could you share the command-line and output?


    3 Jan 14 at 9:45 pm

  27. Will the above discussed method of making an ISO work for OS X 10.9?
    I am feeling hopeful that I can get Windows back on my Mac Mini.


    4 Jan 14 at 9:24 pm

  28. Haven’t tested it yet. I just got my new Mac Mini, and I’ll post something later in the week. 😉


    7 Jan 14 at 3:09 am

  29. Excellent!! Just the thing I was looking for.


    2 Feb 14 at 9:06 pm

  30. Exactly what I needed.. even now.. Thanks!


    7 Feb 14 at 10:25 am

  31. gracias bro, fue de muchisima ayuda..


    24 Feb 14 at 7:17 am

  32. monique chua

    22 Mar 14 at 5:09 pm

  33. If Disk Utility gives you an error in step 2 like: “unable to create [filename].dmg permission denied”, then that is probably due to the disc’s copy protection. In that case try opening the disk first in a program that would be allowed to open it, like VLC (for a video DVD). It worked for me.


    30 Mar 14 at 5:18 am

  34. Thanks! Worked perfectly.


    14 Feb 15 at 6:20 am

  35. If I have a dvd and the dvd contains a series of chapter files which are linked with a menu, how do I convert all those files to a single iso file and keep the linkage?


    10 Jul 15 at 9:29 am

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