I'm lucky: I own a laptop only capable of running Windows Vista. I say this because I had to use said laptop to format an SD card to FAT32 wtih a 32KB cluster, something I found I'm unable to do using the Windows 8.1 Pro formatting tool.

How can I format SD cards, USB thumb drives and hard drives, etc., to FAT32 with a non-Windows-standard cluster size?

During the format on Windows Vista, I returned with an error stating that

The cluster size is too big for the selected file system.

How am I supposed to format FAT32 with a 32KB cluster if that's not physically possible?

3 Answers 3


The result to my query was that apparently, when assigning a cluster size to a FAT32 file-system, the size of the disk is very important.

Disks over 2GB appear to be eligible for a 32KB cluster, whereas their lesser counterparts are not. In order to assign a 32KB cluster on a disk that is less than 2GB in size, you need to use a third-party tool.


HP has a reliable formatting tool for USB drives that is harder to find than you'd think, while SD cards have a dedicated tool.

  • Does the tool allow to format with 32 kB clusters?
    – slhck
    Feb 20, 2014 at 14:03

Using SDCARD Formatter, a sdhc card will format with fat32 and 32k clusters on win 10. Have not tried a SDXC card, but have heard a rumor that the sd card formatter tool defaults to exfat for that.

  • Why do you give this answer if you haven't tried it?
    – Toto
    Jun 21, 2018 at 15:34
  • Because I did try it with a sdhc card, and got a fat32 partition with 32k clusters. That perfectly answers the OP's question.
    – sspence65
    Jun 22, 2018 at 15:42
  • I did format my flash drive (pendrive) with the SDCARD Formatter Indicated by Bad Neighbor and I can confirm that it works. Oct 21, 2018 at 13:49

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