Your “Settings” app may look slightly different depending on which version of Android you run, but for most phones it can be identified by the gear icon.

You can identify the right option by the SD card icon.

If the “Format SD Card” option is grayed out, you will first have to unmount your SD card. Tap on “Unmount SD Card” in this case.

You may see several screens that ask you if you are sure that you wish to format your SD card. Doing so will erase all the content on the card. Follow the prompts to erase and format your card. Once you have formatted, your card will be formatted to FAT32 filesystem type. All your content will be cleared, and you will have a new card formatted to your Android phone. Note: If you are using Android 6. 0 Marshmallow, you will have the option to treat your SD card as either internal storage or portable storage. If you choose to use it as portable storage your SD card will be treated like any other removable storage, allowing you to remove it and transfer files to your computer or another device. If you make it internal, it will be formatted and not be allowed to be read by your computer. Your SD card will be treated as your main storage system. [4] X Research source

You can find your “Settings” app either through the pinned tile on your home screen or from the app list. [5] X Research source Depending on your phone and the firmware you are using, you may have to locate the “Storage Sense” app in the App list. [6] X Research source

The “phone storage” option should show you how much free space you have on your phone and on your SD card. If you clicked on “Storage Sense”, you will see an option for “SD card”.

Formatting your SD card will erase all of the contents of it. Make sure that you have backed up your data elsewhere.

Once you tap on “format SD card” a prompt will appear that warns you that formatting your SD will erase all of your data and files on the card. And it will ask you if you wish to continue. Tap “yes” to format. After the process is complete, your phone will again recognize the card and automatically ask you to reconfigure it. Follow the prompts.

Note that most Micro SD cards that are 32 GB or less come formatted as FAT32. Cards above 64 GB are formatted to exFAT file system. If you are formatting your SD for your Android phone or Nintendo DS or 3DS, you will have to format to FAT32. With Android, many of your apps or custom recoveries, if you are rooted, will not read exFAT. Formatting to FAT32 is usually your best option, however, FAT32 formatted cards won’t let you transfer or store a file more than 4 GB. You can also purchase a third-party micro SD card adapter if you don’t already have one. Just make sure that it is compatible with your micro SD card. Some third-party adapters also use a USB component on one end and operate like a flash drive.

If you are using a micro SD card adapter, make sure that the lock toggle is up and in the unlocked position. If it is in the locked position your computer may not read the card or let you make any changes. It may be “Read only”. It’s a good idea to copy the files currently on the card over to your computer to save. This will allow you to keep your data and files for transferring back after you format.

Once you are in your “Computer” window a list of all your computer drives will display on-screen. Locate your micro SD card. It can be identified by the brand name of your SD card unless you changed the name of your card. If you changed the name, locate it by that name.

If you don’t see a “Format” option you may have to download and install the fat32format utility in GUI version.

If you had to install the fat32utility, you will also see the same box pop up once you have launched the guiformat. exe file. Before you click “Start” make sure that the other tabs and options are correct. Check that the “Capacity” has the right amount of storage. Make sure you are formatting to the desired format, usually FAT32.

Once formatting is complete you will have a blank, newly formatted micro SD card for use.

Note that most Micro SD cards that are 32 GB or less come formatted as FAT32. Cards above 64 GB are formatted to exFAT file system. If you are formatting your SD for your Android phone or Nintendo DS or 3DS, you will have to format to FAT32. With Android, many of your apps or custom recoveries, if you are rooted, will not read exFAT. Also note that if you are using Mac OS 10. 6. 5 (Snow Leopard) or earlier, you won’t be able to use or format an exFAT card as these older versions of Mac OS don’t support this file system. You will have to upgrade your OS. Formatting to FAT32 is usually your best option, however, FAT32 formatted cards won’t let you transfer or store a file more than 4GB. You can also purchase a third-party micro SD card adapter if you don’t already have one. Just make sure that it is compatible with your micro SD card. Some third-party adapters also use a USB component on one end and operate like a flash drive.

If you are using a micro SD card adapter, make sure that the lock toggle is up and in the unlocked position. If it is in the locked position your computer may not read the card or let you make any changes. It may be “Read only”. It’s a good idea to copy the files currently on the card over to your computer to save. This will allow you to keep your data and files for transferring back after you format.

The Disk Utility application will display on-screen. It will show you all of your available drives and storage systems. You can also get to “Disk Utility” by going into your “Applications” Folder > “Utilities” > “Disk Utility”.

Your SD card will show up as a removable disk and display how much space it can hold. Click on your SD card drive to bring up a page with a list of options.

You will see three or four radio button options at the top: “First Aid” “Erase” “Partition” “RAID” and “Restore”. You may also see “Unmount” if you are running El Capitan. You want to click “Erase”.

You will have options for Mac OS Extended (Journaled), Mac OS Extended (Case-Sensitive, Journaled) MS-DOS (FAT), and exFAT. MS-DOS (FAT) is the option that formats your micro SD to FAT32. [10] X Research source The exFAT option will format to the exFAT filesystem and allow you to transfer and store files larger than 4 GB. After you select your desired format, enter a name for your card.

Once you click “Erase” your computer will format and erase your card. Once it is complete it will show up with the new name. Your micro SD card is now formatted.