What are the theoretical and practical minimum sizes for a FAT16 volume?

I'm trying to determine the smallest Flash-chip size that can handle a FAT16 FS.


If I remember correctly it's 4.1MiB (1,048,576 bytes*4.1 = 4,299,161.6 bytes).

  • That's correct. It is either 4.1MiB or equivalently 4.3MB. If you would also like the max size, it is (on a NT/2000/WinXP machine) 4GiB or 4.29GB.
    – Marcin
    Nov 23 '09 at 19:06
  • Ah! So it makes sense that my FAT driver throws error at about 4MB. Where does the 4.1 come from?
    – MandoMando
    Nov 23 '09 at 20:13
  • The minimum number of sectors is 8401, so the correct minimum byte count (sector size = 512 bytes) is actually 4,301,312. That gives 4.10205078125 MiB.
    – monkey0506
    Feb 2 '16 at 18:15

4.1 MiB is correct, however you could go smaller with FAT12, which is still readable by modern OS's.

  • I would, though I hear implementing a FAT12 driver is not easy.
    – MandoMando
    Nov 23 '09 at 20:14

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.