How Many Extended Partitions Can Be Created in a Hard Drive?

"Recently, I'm trying to create partitions for my new hard drive because I know partitions are important if I want to store data on it. However, I got in trouble, I exactly know there must be primary partition to store operating system but I don't understand how many extended partitions can be created in a hard drive? If possible, I want to create more extended partitions to store my files and documents. Is my thought available?"

Extended partition definition

The reason why many users are asking "How many extended partitions can be created in a hard drive?" is that they don't know much about the partition of a drive. To know what is the maximum number of extended partitions can you have on a hard drive, let's talk about the following two questions first.

What is partition?

When you run a computer, there must be a place to store all of the files that make up an operating system so that your hard drive knows how to find them to keep your computer running smoothly. This process is called partitioning, the place can be a partition.

Usually, a drive comes with a partition which often takes up the entire drive by default, or we can say there must be at least one partition on a drive. However, a single partition will treat your drive as a single unit, you may feel inconvenienced when needing to find various types of files. Therefore, you may require different numbers of partitions for various reasons. And the number of partitions is related to the two partition styles: MBR and GPT. Only on the MBR disk, there goes with three kinds of partitions: primary partition, extended partition, and logical partition.

What is an extended partition on a hard drive?

The extended partition, a special type of primary partition, is designed for users who wants to create more partition than the allowed 4 primary partitions on an MBR disk. Unlike a primary partition, you don't have to assign it a drive letter like "C:" or "D:" because we usually consider an extended partition as a container that includes all the remaining free space on the drive.

 As we know, unallocated space cannot be used to store data before it's partitioned. Therefore, to manage your storage space better, you can create logical drives assigned with drive letters inside the extended partition so that you can get more partitions in total. In other words, the extended partition is not used to store data directly but to hold logical drives.

How many extended partitions can be created in a hard drive?

As we described above, any disk with storage space must be partitioned with at least one partition before it can be used. On an MBR disk, there can only be four primary partitions. To break the limitation, you can change any one of the four primary partitions into an extended partition.

So how many extended partitions can exist on one drive? We have mentioned that the extended partition functions as a container including all the remaining free space, so only one extended partition can be created in a hard drive. That's why we usually note that you can have four primary partitions or three primary partitions and one extended partition(with many logical partitions) on an MBR drive.

If you still want more partitions on MBR, the main factor is how many logical partitions can be created in an extended partition. In theory, you can create an infinite number of logical drives, but in fact, it depends on the amount of free space available on the extended partition and the number of drive letters you can use to define.

However, if you are using a GPT disk, you have no such worries because GPT can have up to 128 primary partitions and support volume up to 9.4ZB in size, which is totally enough for normal use. To this end, if you want to create more partitions on a drive, the most feasible and easiest way is to convert the partition scheme from MBR to GPT.

Convert MBR to GPT to create more partitions

As mentioned above, on an MBR disk, you can create four primary partitions or three partitions and one extended partition with a number of logical drives on it while GPT formatted disk doesn't have this limit because it can have 128 primary partitions at most. So the convincing reason for converting MBR to GPT depends on the differences between logical drives and primary partitions.

Why need to convert MBR to GPT: logical drives vs primary partition?

Basically, a primary partition is one that can be used as a system partition where the boot files of the operating system must reside on. An active partition for initial booting is based on the primary partition. Furthermore, you can use a primary partition to store files and documents.

However, logical drives, also called logical partitions, are sections inside an extended partition to store data. It won't affect to access other partitions on the same physical hard drive and cannot host an operating system. Therefore, the obvious merit of primary partition is its compatibility in storing operating systems.

How to convert MBR to GPT to create more partitions?

We have known that our data are all stored on the partition, so converting MBR to GPT without data loss is dramatically important. You may want to use Windows built-in tools like DiskPart.exe and Disk Management, but they only allow you to convert non-system disk or the disk with no partitions from MBR to GPT, which requires you to delete existing partitions (along with inside data) beforehand. It is easy to cause data loss.

Here a powerful partition manager called AOMEI Partition Assistant Professional is highly recommended to you. With the help of this software, you can easily convert both the system disk and data disk between MBR and GPT without deleting partitions. Now, download it and have a try:

Step 1: Install and launch AOMEI Partition Assistant Professional, right-click the MBR disk you want to convert and select "Convert to GPT".

Step 2: In the pop-out window, you will be asked are you sure to convert the selected disk from MBR to GPT disk. Click "OK" to continue.

Step 3: When back to the main console, click "Apply" to commit the operation and you will find your disk style has been changed into GPT.

Note: Since GPT works with UEFI boot mode, so please make sure your boot mode is UEFI or has been changed from Legacy BIOS to UEFI, otherwise, the system won't work after changing.

Conclusion

How many extended partitions can be created in a hard drive? Now you may get the answer: Only one extended partition is available on an MBR disk. Due to the limitations: the number of drive letter and the edge of primary partition, if you want to create more partitions, the most reliable way is to convert MBR to GPT. AOMEI Partition Assistant Professional recommended above can help you realize it without data loss, and will provide you with more functions: upgrade HDD to SSD, migrate OS from MBR disk to GPT SSD or HDD, and allocate free space from one partition to another.