如何恢复或格式化SD卡至完整容量

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Linda 

Written by

Linda 

Updated on April 22, 2024

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Reasons for SD Card Not Displaying Full Capacity

The same case can occur on other storage devices like USB flash drive, pen drive, hard drive, memory card, etc. Why does my SD card not show its full capacity? How can I restore the SD memory card to full size? Users often ask such questions when they encounter this strange issue.

通常，SD卡未显示完整容量是因为某些读卡器或主机设备与较大的SDHC和SDXC卡不兼容。如果读卡器或主机不支持更大的容量，该卡将被重新分区为受支持的大小。例如，如果你的读卡器或相机与使用此读卡器或相机格式化的最大容量为32GB的SDHC卡兼容，那么将64GB的SDXC卡格式化为32GB（可用容量约为27GB）。此外，由于不可见的阴影文件、格式化开销、隐藏的恢复分区和未分配空间，SD卡也可能未显示完整容量。

If you're encountering issues similar to an SD card not displaying its full capacity, don't fret! There's a solution. You can utilize a reader or host that fully supports the card's capacity and employ a third-party SD card formatting tool to effortlessly restore the full capacity of SDHC/SDXC cards. Additionally, you can use the Diskpart command to repair the card.

Extended Reading: SSD Reports Incorrect Size

Method 1: Restore SD Card to Full Size with Partitioning Tool

To assist you in recovering lost or unallocated space and securely and effortlessly restore your SD card to its full capacity/original size, we recommend using the tool Partition Master, a powerful disk management utility that enables formatting of hard drives and conventional removable storage devices. Follow the simple guide below to reformat your SD card and regain its full capacity with this tool.

Step 1. Launch AOMEI Partition Assistant, right-click the partition on your external hard drive/USB/SD card that you wish to format, and select the "Format" option.

Step 2. Assign a new partition label, file system (NTFS/FAT32/EXT2/EXT3/EXT4/exFAT), and cluster size to the selected partition, then click "OK".

Step 3. In the Warning window, click "Yes" to continue.

Step 4. Click the "Execute 1 Task(s)" button in the top-left corner to review the changes, and then click "Apply" to begin formatting your external hard drive, USB, or SD card.

更多选择适合SD卡的文件系统的建议：

• FAT32 - Suitable for 2-32GB memory cards. (Optimal choice)
• NTFS - Suitable for SD cards of almost all sizes, up to 2TB.

Method 2: Repair an SD Card Showing Less Space via Command Prompt

The introduced SD Card Formatter should ideally help you restore your memory card to its original size. Although this is the simplest and most effective method for dealing with a removable hard drive that displays less disk space than it actually has, there is an alternative approach. The Windows Command Prompt, which necessitates a higher level of computer proficiency compared to using a third-party automated tool, does not require downloading or installation. It is a built-in native Windows tool available for anyone with administrative privileges to utilize.

To troubleshoot the SD card that has somehow lost some valuable storage, you can use the DISKPART command lines to recreate a new volume by diligently following each step.

Step 1: In Windows 10, for instance, type cmd in the search bar. This should display the best match, which is the Command Prompt. Right-click on it and select "Run as administrator".

Step 2: In the Command Prompt black window, type diskpart and press "Enter".

Step 3: Type list disk and press "Enter". This will list all the disk drives, including the SD card connected to your computer.

Step 4: Referencing the disk information list, type select disk + disk number, for instance, type 'select disk 2' and hit Enter. This instructs Diskpart to format disk 2.

Step 5: Type clean next. This step begins to clean all files and folders on the selected hard drive.

Step 6: Type create partition primary and press "Enter".

Step 7: Once diskpart successfully creates the partition, type format fs=ntfs (or format fs=exfat) and press "Enter". This instructs diskpart to format the drive with a file system, such as NTFS or exFAT.

Step 8: Finally, assign a drive letter to the newly created partition by typing assign.

Additional tips for running Diskpart smoothly:

• You must run Diskpart as an administrator. Otherwise, Windows will prevent you from running it correctly. There's another way to open the Windows Command Prompt: press Windows + X keys, then select Command Prompt (Admin).
• For handling the other common error, refer to this article: Diskpart has encountered an error: Access is denied.

Does this method resolve the "SD card showing less capacity" issue for you? If so, please share this article to assist others who encounter the same problem.

Method 3: Repair an SD Card Showing Less Capacity via Disk Management

To restore an SD card to its factory settings, please follow these steps for disk management:

Step 1. Press Windows+R > Select Disk Management.

Step 2. Right-click on the SD card and choose Format.

How to Reclaim Full Capacity of an SD Card on a Mac

When it comes to repairing an SD card showing less capacity, here's a guide on how to reset an SD card.

Step 1: Open the Disk Utility app.

Step 2: Select your SD card and choose Erase.

Step 3: Choose File system > Erase.

Following this, your SD card will display its full storage capacity on your computer, and you'll be able to save as many files as you wish onto the device.

?Explore More: Solved: Ender 3 Not Reading SD Card [Quick Fixes]

Conclusion

On this page, we have presented 4 dependable methods to help you address the issue of an SD card not displaying its full capacity on both Windows and Mac computers.

For a Windows computer, the optimal solution to fix an SD card not displaying its full size is to utilize the tool Partition Master.

For Mac users, the most effective tool to handle an SD card displaying incorrect space is to use Disk Utility to format and erase the drive to its full capacity.

FAQs About SD Card Not Showing Full Capacity

If you have any further questions regarding this issue, please refer to the questions below and find the answers provided.

**1. How do I fix the issue of an SD card not showing its full capacity?**

Translate the following text into English, focusing solely on the translation task:
• Connect the SD card to your computer.
• Open File Explorer to find the SD card volume, then open it and back up all important data from the SD card to another drive.
• Right-click on the SD card and choose "Format."
• Check "Perform a quick format" and assign a new file system to the SD card.
• Click "Start" and then "OK."

< strong > 2. Why does my memory card show less capacity than specified?

The reason a storage device or drive appears to have less capacity than advertised is due to the different ways storage capacity is calculated compared to other measurements in computing. In a storage device, 1 GB is considered to be 1,000,000,000 bytes, whereas in computing, 1 GB is calculated as 1024 MB, which equals 1,048,576 KB or 1,073,741,824 bytes.

For example, let's take a 250GB memory card as an example to illustrate the differences:

• Advertised memory card capacity: 250GB
• Windows-reported memory card capacity: 233GB

This is why your memory card displays less capacity than advertised.

3. Why does my 16GB SD card show 14GB? This is because the storage capacity advertised for SD cards is usually based on the decimal system (1 GB = 1,000,000,000 bytes), while the operating system uses the binary system (1 GB = 1,073,741,824 bytes). As a result, when you insert a 16GB SD card into your device, the actual available space appears to be less due to this difference in calculation. Additionally, the card has some space allocated for file system and system use, which further reduces the visible storage.

The 16GB mentioned for the SD card refers to its storage capacity, measured in bytes, whereas the 14GB displayed on your computer represents the computed storage, calculated in gigabytes. Typically, when a memory card states 16GB of storage, it appears as approximately 14.9GB on a computer due to the difference in calculation methods. This is why a 16GB SD card might show up as 14GB on a computer.