Microsoft small business knowledge base

Article ID: 192322 - Last Review: June 22, 2014 - Revision: 2.0


This article lists the default cluster sizes for drives using the FAT32 file system. The FAT32 file system uses smaller default cluster sizes than the FAT16 file system, resulting in a more efficient file allocation system and the conservation of drive space.

More information

The following tables lists the default cluster sizes used by the FAT32 file system.

   Partition size           Cluster size
   512 MB to 8,191 MB          4 KB
   8,192 MB to 16,383 MB       8 KB
   16,384 MB to 32,767 MB     16 KB
   Larger than 32,768 MB      32 KB

Note that the FAT32 file system does not support drives smaller than 512 MB.


For more information about the FAT32 file system, see the following articles in the Microsoft Knowledge Base:
ARTICLE-ID: 154997  ( )
TITLE : Description of the FAT32 File System

ARTICLE-ID: 69912  ( )
TITLE : MS-DOS Partitioning Summary
Note This is a "FAST PUBLISH" article created directly from within the Microsoft support organization. The information contained herein is provided as-is in response to emerging issues. As a result of the speed in making it available, the materials may include typographical errors and may be revised at any time without notice. See Terms of Use ( for other considerations.
kbinfo KB192322
Additional support options
Ask The Microsoft Small Business Support Community
Contact Microsoft Small Business Support
Find Microsoft Small Business Support Certified Partner
Find a Microsoft Store For In-Person Small Business Support