How To Determine Your Hard Disks Cluster Size

This article explains how to determine your hard drives cluster size.

To determine your hard drives cluster size, perform the following steps:

1. Click Start, point to Programs, and then click MS-DOS Prompt. For Windows Me, Click Start, point to Programs, point to Accessories, and then click MS-DOS Prompt.
2. Type chkdsk, and then press ENTER.
3. Note the number next to the bytes in each allocation unit line.NOTE: The bytes in each allocation unit is your cluster size. To obtain the cluster size in kilobytes (KB), divide the number you noted by 1024.
   
   For example, if Chkdsk shows 4,096 bytes in each allocation unit, then your cluster size is 4 KB.
   4,096 bytes / 1,024 bytes per KB = 4 KB
4. At the command prompt, type exit, and then press ENTER to return to Windows.

For additional information about clusters and the FAT file system, click the article numbers below to view the articles in the Microsoft Knowledge Base: