How to Fix SD Card Showing Wrong Size | Restore SD Card to Full Capacity

Why My SD Card Shows the Wrong Size?

Question

I’ve been using a 128GB SanDisk SD card in my Nintendo Switch for about a year. Today I plugged it into my PC to move some clips, and Windows shows the card as 16GB total capacity. That's not true. What happened? Has anyone had an SD card that shows wrong size like this? Any help appreciated!

An SD card showing the wrong size usually means something has gone wrong with the way the card is read, formatted, or partitioned. This issue can happen on any device, and Here's why your SD card showing less space:

• Counterfeit or low-quality card: Some fake cards are labeled with a higher capacity than they actually have, making the size to show abnormally.
• Corrupted or altered partitions: The card’s partition table may be damaged, so the device can’t read the full capacity.
• Improper formatting by a device: Cameras, phones, or consoles may format the card in a way your computer can’t fully recognize.
• File system corruption: Bad sectors, sudden removal, or power loss can break the file system, making the card report incorrect size.
• Host and reader compatibility: Some devices or card readers can’t handle high-capacity cards (like SDHC or SDXC) properly. When this happens, the device may repartition the card or misread its size.

When an SD card reports the wrong size, there are several ways to tackle the problem. You might check and repair its partitions, format it correctly, or use dedicated tools to scan for hidden errors. In some cases, replacement may be the only option if the card is physically damaged.

How to Recover Files from an SD Card Showing Wrong Size?

Before attempting to fix an SD card that shows the wrong size, it’s crucial to secure your data. Many of the methods used to restore the card can erase everything stored on it. To avoid losing precious photos, videos, or documents, it’s strongly recommended to recover all files first.

A reliable tool for this is 4DDiG Data Recovery, which supports recovering data from all types of storage devices, including formatted SD cards, USB flash drives, external hard drives, HDDs, and SSDs. It can recover all kinds of files, even if the SD card is not showing the correct size or has become corrupted.

Using 4DDiG ensures your important data is safely restored before you try any repairs. In the steps below, we’ll show how to recover files from an SD card showing the wrong capacity before moving on to fix the card itself.

• Connect your SD card or storage card to your computer and launch 4DDiG Data Recovery. Select the SD card, then click "Scan" to start searching for all available data.
• The software will automatically perform a deep scan, so there’s no need to worry even if file names are missing. Once the scan is complete, you can browse all the recovered data in the tree-view panel on the left. If you’re looking for a specific type of file, simply use the "Filter" option.
• After finding the files you want, you can double-click them to preview. Then select the files you need and click the "Recover" button.
• When prompted, choose a safe location to restore your data, either on another external storage device or in cloud storage.

You can also watch the video directly to see how to recover and save your files from the problematic SD card:

How to Fix SD Card Not Showing Full Capacity?

To restore an SD card to its full capacity, a quick format is often required. However, formatting must be done carefully, as it will erase all data on the card. If you don’t have a backup, the data will be lost after formatting.

Therefore, make sure to create a backup beforehand. Otherwise, you’ll need to use 4DDiG to recover files from the formatted SD card. Below are the methods that can help you format yourthe SD card and fix the SD card wrong size issue.

1 Format SD Card via File Explorer

If your SD card can be recognized by Windows and you just need to fix minor file system issues that cause your SD card showing wrong capacity, formatting via File Explorer is the quickest and simplest option.

This method allows you to erase the card’s contents and set the file system without dealing with partitions or advanced tools. Below are the detailed steps.

• Plug your SD card into your computer using the built-in card slot or an external card reader.
• Open "File Explorer" by pressing Win + E.
• Find and right-click the SD card and select "Format" from the context menu.
• Choose the File System you need then set the "Allocation unit size" to Default.
• Check "Quick Format" for a faster format, or leave it unchecked for a full format.
• Click "Start" to begin formatting.

2 Format SD Card via Disk Management

When the micro SD card showing wrong size, formatting via Windows Disk Management can be a more powerful solution than File Explorer. This built-in tool allows you to delete existing partitions, rebuild the partition table, and format the drive with the correct file system.

However, this method works only if the issue is partition-related or minor corruption. It won’t fix physically damaged or counterfeit cards. Let's see how to restore your SD card to full capacity in Windows 10/11.

• Open "Disk Management" by searching for it in the Windows Start menu.
• Identify your SD card and delete all its existing partitions (make sure you only delete the SD card's partitions).
• After deleting, the SD card will appear as a single "unallocated partition" at the bottom of the Disk Management window.
• Right-click the unallocated space and select "New Simple Volume", then click "Next".
• Set the "volume size" (it defaults to the full capacity of the SD card) and click "Next".
• Assign a drive letter and enter a volume label, then click "Next".
• Choose a "file system" (FAT32, exFAT, or NTFS), confirm the settings, and click "Finish" to format the SD card and complete the process.

Notes

If you only want to format the existing partition and doesn’t want to remove or recreate partitions, here's how to perform a simple format with Disk Management:

Open Disk Management > Locate your SD card and right-click on it to select "Format" > Choose the "File System" > Enter a Volume label to name your SD card > Check "Perform a Quick Format" to start.

3 Format SD Card via DiskPart

When the SD card isn’t formatting properly with File Explorer or Disk Management, you can use Windows’s built-in command-line utility - DiskPart. It is more powerful when other methods fail or when you really need to restore your SD card to full capacity. Here's how to fix SD card showing wrong size with Disk Part.

• Go to the Start Menu, type "cmd," right-click on it and select “Run as administrator."
• Type the DiskPart in the cmd and hit "Enter".
• Type List Disk in the cmd to show all the available disks, including the SD Card.
• Now, note the disk number of your SD card, type select disk followed by the disk number, and hit "enter" to run the command to select your SD card.
• Type the command Clean and proceed to run it to erase everything on the SD Card.
• Now create a new partition on your sd card. To do so, type create partition primary and press "Enter".
• Type the command format fs=ntfs and hit the "Enter" button to assign a file system to the SD Card.
• Finally, assign a letter to your SD card by typing the command sssign letter=F to choose a letter to your SD card.

How to Fix an SD Card that Won't Format?

When the SD card won't format, you can check the following reasons and solutions. Some SD cards come with a switch/lever that needs to be pulled or pushed. Examine your SD Card properly, and see if there’s any button or switch on it.

Another reason can be the SD card is in read-only mode. You can only access the already stored data on the SD card but can’t write/save anything new on it. It can be resolved using the following steps:

Open the Command Prompt, then type the chkdsk h: /f command in the CMD. Make sure to replace the letter "h" with your SD card before running the command.

Conclusion

This article has covered 3 practical methods to fix the SD card showing wrong size problem, including formatting via File Explorer, Disk Management, and DiskPart. Always back up your data before making changes, but if the card has already been formatted, Tenorshare 4DDiG can reliably recover files from SD cards, even those with incorrect capacity or corruption.