[Reasons & Steps] Why Format SD Card and How to Format?

Why format SD cards? This post will answer the question and share you easy methods to format an SD card to FAT32, NTFS, and other formats you need in different situations.


By Irene / Updated on February 4, 2024

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When you insert a new SD into a device, especially an Android device, it will generally prompt you to format the card, and it says this is necessary for the card to work properly with your device. But why format SD card is necessary? In this passage, we will answer you with step-by-step guidance for easily formatting an SD card.

Why format SD cards?

If you've used an SD card, you know you have to "format" it first. But what does that mean, and why is it necessary?

In many situations, you might have to change the format of your SD card to NTFS, FAT32, or exFAT. Formatting clears everything on the SD card to make sure it works well with your device and prepares it for new data. This helps keep the SD card running smoothly and prevents issues like data errors or slowing down.

1. Formatting the SD card can ensure compatibility with different devices such as cameras, smartphones, game consoles, music players, and more.
2. Regular formatting also helps the SD card last longer by reducing wear and tear on its internal components, protecting it from potential damage.
3. Formatting also helps by clearing out unnecessary files and fragments, which makes storage space efficient for storing and accessing data.

For these reasons, it's important to format your SD card regularly for optimal performance and data integrity. That's why it's necessary to format a new SD card before using it.

However, there may be instances when you cannot format the SD card. "Why can’t I format my SD card?" Generally, this could be due to the SD card being infected with a virus or malware, the SD card being write-protected, SD card larger than 32GB, or bad sectors on the SD card. You may receive messages like the ones below:


How to format an SD card?

Now that you know why format an SD card, let's explore how to do it. We'll share 2 methods for different situations. If your SD card is smaller than 32GB, both methods will be suitable. However, if the SD card is larger than 32GB, only method 1 will work, as you may encounter an error message otherwise.

Case 1. Format an SD card larger than 32GB

If your SD card is larger than 32GB and you want to format it to FAT32, you can't do it with Windows' built-in tool. That's because Windows doesn't support formatting drives larger than 32GB to FAT32.

In this situation, you can use third-party software like AOMEI Partition Assistant Standard. It's simple to use and can format large SD cards, like 64GB or 128GB, to FAT32 quickly. It also offers different file systems to choose from, such as NTFS, FAT32, exFAT, Ext2, Ext3, and Ext4.

Most importantly, it offers a Check Partition function to identify any errors causing formatting failures. If you encounter file system corruption leading to the SD card being write-protected, the software also allows you to force format the SD card effortlessly.

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Step 1. Run the installed software, right-click on the SD card partition, and choose "Format Partition".

Format Partitoin

Step 2. Select the file system of your choice, then click OK.


Step 3. Return to the main interface and click on "Apply" to confirm and execute the operation.


While formatting, you have the option to format the SD card into NTFS, FAT32, Ext2/3/4, and exFAT. AOMEI Partition Assistant provides nearly all the required file systems, rendering it a superb tool for formatting SD cards.

Case 2. Format an SD card smaller than 32GB

If you are familiar with the CMD and your SD card is smaller than 32GB, you can format it using Diskpart.exe. On your Windows PC.

Step 1. Type "cmd" in the search box. Right-click on Command Prompt and choose "Run as administrator".  In the command prompt, type "diskpart" and press "Enter".

Step 2. Type "list disk" to list all the available drives on your computer and press "Enter".

Step 3. Type "select disk n" (where "n" refers to the disk number of your SD card) to select the SD card you want to format and press “Enter”.

Step 4. Type "clean" to clean the SD card you have selected and press "Enter".

Step 5. Type "create partition primary" to create a partition on the cleaned SD card and press "Enter".

Step 6. Type "format fs=ntfs" (or "format fs=exfat") and press "Enter" to format the drive with NTFS or exFAT.


If you want to assign a drive letter to the SD card, you can type "assign letter n." (for example, assign letter=f.) to assign a drive letter and press "Enter".

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This post explains why format SD cards and shares how to do it. It is recommended to use the free and powerful software AOMEI Partition Assistant for a quick and safe way to format an SD card. You can also upgrade to the AOMEI Partition Assistant Professional edition to enjoy more advanced features such as App Mover, Clone Disk, Allocate Free Space, Convert MBR/GPT without data loss, etc.

If you are a Windows Server user who want to effectively manage your computer, this software offers the Server edition.

Irene · Staff Editor
Irene is an Editor of AOMEI Technology. She devotes herself in giving insightful thoughts on common computer problems with simple and clear guidance. Irene loves to help people solve problems and explore more solutions on relevant issues. She loves reading, singing and travelling.