How to Convert DMG to ISO on Mac and Windows [3 Proven Ways]

"How can I convert the DMG to ISO format on Mac OS X? Is it possible to do it within Disk Utility or CLI easily, or do I need an external utility?"

This is a common question from many users. Apple uses the DMG format to distribute software and secure data. Windows can't open DMG files natively, which is a major hurdle if you need to access Mac-based software on a PC. To fix this, you must convert DMG to ISO format, which is universal and compatible on macOS, Windows and Linux. I've tested several DMG to ISO converters, and these three are the most reliable ways to get the job done. Read on to learn how to convert DMG to ISO step by step.

What are DMG and ISO Files?

Before diving into the conversion process, it is essential to understand why converting DMG to ISO is necessary. While both serve as digital clones of physical discs, they were designed for different ecosystems.

DMG is Apple's proprietary disk image format. When you download Mac programs from official websites, you almost always get a .dmg file. After double-clicking it, a virtual disk icon appears on the desktop; you simply drag the program icon into the "Applications" folder or run the installation script inside. DMG files are highly "intelligent"; they contain raw data blocks and utilize various compression algorithms to reduce size. More importantly, it supports advanced encryption; if you have private files, you can create a password-protected DMG. However, it is fundamentally tailored for Mac, and Windows cannot recognize it natively, which is the primary reason users seek DMG to ISO converters.

ISO is a complete image of an optical disc. ISO is the "universal language" of the file world. In Windows 10 or 11, you can right-click to mount an ISO directly, and the system will treat it as an inserted physical disc. It is commonly used to emulate DVD drives or to store Linux installation images, making it easy to burn to a USB drive to create a bootable disk. Unlike the DMG, ISO is very accessible; it not only runs perfectly on Windows but is also natively recognized and read on macOS.

So, if you receive a DMG file containing important data or software on a Windows computer, you will find that it cannot be opened directly. Converting DMG to ISO is the most reliable solution. Below I will introduce three proven methods to convert DMG to ISO on Mac and Windows, include using Disk Utility, the Terminal, and the dmg2img DMG to ISO converter.

1. How to Convert DMG to ISO on Mac with Disk Utility

For Mac users, the most straightforward and reliable way to convert .DMG to ISO is by using the built-in Disk Utility. Since this tool is pre-installed on every macOS, you don't need to download any third-party software. This method is ideal if you prefer a graphical interface. It essentially re-packages the DMG into a DVD/CD Master format, which creates a file that can be easily renamed to an ISO. The following section shows how to turn DMG to ISO with macOS Disk Utility.

Step 1: Mount the DMG File

Locate your DMG file and double-click it to mount it as a virtual drive on your desktop.

Step 2: Launch Disk Utility

Open Finder, go to Applications > Utilities, and select Disk Utility.

Step 3: Initiate Conversion

In the Disk Utility sidebar, locate the mounted DMG image. Right-click on it and select the Convert option from the menu.

Step 4: Configure Output Settings

In the dialog box, select DVD/CD master from the dropdown list. Ensure this is set to "none" for maximum compatibility unless you specifically need to password-protect the file.

Step 5: Convert DMG to ISO

Choose your destination folder and click Save. Disk Utility will begin creating a new file with the .cdr extension.

Once the process is finished, locate the new .cdr file. Since a CDR is functionally identical to an ISO, simply click the filename and change the extension from .cdr to .iso. Click "Use .iso" when the confirmation prompt appears.

2. How to Convert DMG to ISO on Mac with Terminal

If Disk Utility feels sluggish or you need to automate the conversion process, the command-line interface (CLI) offers a more stable way to convert DMG to ISO. It allows for precision and speed, especially when dealing with large files. Plus, terminal is often more successful than Disk Utility when dealing with "read-only" or "compressed" DMG files because it bypasses some of the GUI's security prompts and mounting requirements. In fact, converting DMG to ISO this way isn't as difficult as it sounds. Follow these steps to perform the conversion via the command line.

Step 1: Open Terminal 

Navigate to Applications > Utilities > Terminal, or simply search for "Terminal" using Spotlight (Cmd + Space).

Step 2: Unmount the DMG Image 

Before starting the conversion, ensure the DMG file is not currently mounted or "open" on your desktop. If the disk image icon is still visible, right-click it and select Eject to avoid "disk image failed" errors during the process.

Step 3: Enter the Hybrid Conversion Command 

Type the following command into the window, ensuring you replace the placeholders with your actual file names: hdiutil makehybrid -iso -joliet -o [output_filename].iso [source_filename].dmg

Step 4: Convert .dmg to .iso

Once your command is properly formatted with both the output and source paths, press Enter. Terminal will begin the conversion process and directly generate a standardized .iso file. This file is now ready for cross-platform use and does not require manual renaming.

3. How to Convert DMG to ISO on Windows with dmg2img 

dmg2img can be used to turn DMG to ISO files and vice versa. This method requires a bit of command-line work, but it is the most reliable way to ensure the data inside the DMG remains intact during the transition to ISO. Follow these steps to install and use dmg2img to convert DMG to ISO.

Step 1: Download DMG to ISO Converter

Visit the official dmg2img website and download the latest binary ZIP file. Note that while the DMG to ISO tool is typically a 32-bit executable, it runs perfectly on 64-bit versions of Windows 10 and Windows 11.

Right-click the downloaded ZIP and select Extract All.... After extracting, you will have a new folder (e.g., dmg2img-1.6.7-win32). Note the name of this folder, as you'll need it for the next step.

Step 2: Open Command Prompt as Administrator

Press the Windows Key, type cmd. Right-click Command Prompt and select Run as administrator. Then, use the following command to jump straight to your extracted folder (replace Folder_Name with the actual name of the extracted folder): cd /d %USERPROFILE%\Downloads\Folder_Name

Step 3: Convert DMG to ISO

Use the following syntax to convert your file: dmg2img <sourcefile.dmg> <destinationfile.iso>

• Example: If your source file is named MacInstaller.dmg and you want to convert it to WindowsReady.iso, enter the following command: dmg2img MacInstaller.dmg WindowsReady.iso

Once you press Enter, the tool will display a progress percentage. When it reaches 100%, your ISO file is ready in that same folder.

How to Use and Play ISO After DMG to ISO Conversion

After converting DMG to ISO, how do you use these converted file? In fact, the exact method depends on the content of your ISO file.

1. For Software and Data (Program ISOs)

If your original DMG was a Mac application or a collection of files, you don't need a media player. Instead, you need to mount the ISO so your computer treats it like a real disc.

• On Windows 10/11: Right-click the ISO file and select Mount. A new drive letter will appear in "This PC," allowing you to browse the files and run installers.
• On macOS: Double-click the ISO file. It will appear on your desktop as a virtual disk, just like the original DMG.

2. For Movies and Media (Video ISOs)

If your ISO contains a DVD/Blu-ray structure, simply "mounting" it often isn't enough to enjoy the full experience, such as interactive menus and high-definition audio. This is where a dedicated player like PlayerFab DVD Player is essential. PlayerFab DVD Player is specifically designed to handle the complexities of video ISO files on both Mac and Windows.

Conclusion

The best way to convert DMG to ISO depends on which computer you use and how comfortable you are with technical tools. If you use a Mac and want something simple, Disk Utility is the easiest choice. For Mac users who need a file that is guaranteed to work on Windows, the Terminal is more reliable. If you are on a Windows PC, dmg2img is the best tool to open those Mac-only files without needing a Mac at all. Once converted, you can mount the ISO directly to open your files or use a media player to play video ISOs.