FAT32 file size limit

Here is a quick 50 points. What is the maximum file size limit for fat16 and fat32? I have tried to copy a 4gb file to a fat32 drive but it pukes. I suspect it is a file size limit.

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FAT16 has a 2GB file size limit, FAT32 has 4GB as its limit. So you would be correct in assuming the file size is the problem here.


The file size limitation appears to be the problem,
but the maximum size depends on the operating system.
What is the size of the file you're copying and where does it reside?

The maximum file size on a FAT32 formatted partition is
4 GB or 4,294,967,296 bytes minus 2 bytes ...

The maximum file size on a FAT16 partition
under Windows 9.x and ME is 2 GB minus 1 byte ...

But the size limit using the FAT16 file system
under Windows NT or 2K is 4 GB ...

And the NTFS file system has a (theoretical) maximum file size of
16 exabytes or 18,446,744,073,709,551,616 bytes (2^64 sectors) ...

Please post back if you need more info on it
or perhaps workarounds for managing the file...

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jhiebAuthor Commented:
Thank you. This is what I needed and I will accept your answer. If you know this on the top of your head, are there special characters that are allowed on an NTFS system that are not allowed on a FAT16 or FAT32 file system?
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Do you mean special characters in a filename?
Certain characters would apply to the OS
such as Windows 9.x and NT
which disallows some,
including these:

    \  /  ?  :  "  *  <  >  |

NTFS uses the 16-bit Unicode character set
and some special characters are allowed
but a few are still illegal under DOS ...

I believe valid characters under 9.x and NT include:

  @  &  ^  '  ,  {  }  [  ]  $  =  !  -  #  (  )  %  +  ~  _  .

So special characters may be allowed on an NTFS
that aren't allowed on a particular operating system.

Post back if it doesn't help and someone will probably know...

You mention that the file size limitation is a function of the operating system.  The operating system you didn't mention was DOS.  If I boot a DOS disk, what is the limit on file size for FAT16 and FAT32?  2GB and 4GB?

Pure DOS does not support FAT32, only FAT16. And yes, 2GB is correct.
Thanks, SunKing!

Here's another one.  Let's say I boot a networkable DOS disk and try to save a file larger than 2GB to an NTFS volume on a server.  Will that work?

You really should open a new question for issues unrelated to the original question already answered.


Each OS I refer to is "DOS," which is merely an acronym for
Disk Operating System. My comments pertain to variations of MS-DOS.

Versions of MS-DOS 7 and later (Windows 95 and above) support FAT32...
Under these versions the 4GB file size limit will apply.

MS-DOS versions prior to DOS 7.0 (e.g., 5.0, 6.x)
are subject to the FAT16 file size limit of 2GB.

You ask what the file size limit would be if you "boot a DOS disk"...
As noted, this would depend on what version of DOS you're booting.

The file creation process will fail with an "Access Denied" error
if the file size exceeds the limit of the particular OS you're running.

Regarding your other question about creating or copying
a 2GB file to an NTFS partition...
This is definitely no problem, as the theoretical maximum file size
under an NTFS, as previously mentioned, is 16 exabytes.

The number of bytes in an exabyte is two to the sixtieth power,
or 1,152,921,504,606,846,976 bytes. "Exa" is a prefix meaning
one billion billion, which is the same as one quintillion.
Two the sixtieth power is really a little more than a quintillion.
So an exabyte is approximately a billion gigabytes.
Thus 16 exabytes is approximately 16 billion gigabytes.

This is in theory because the size of an NTFS volume
is also limited by the practical implementation of the OS,
as well as restrictions due to the partitions cluster size.

It's also theoretical because nobody has ever been able to try it.
But on an NTFS the file size is limited only by the size of the volume.

Also note that if you boot with a disk having a version of DOS
preceding DOS 7.x, you won't be able to see a FAT32 partition
to access a file, regardless of its size.

But if you intend creating or copying files of this size
to a server on a network, I recommend you bring a lunch!

Hope this helps... Please post back if you need more...

Thanks, rin!  That answers my question most thoroughly!  I should have taken SunKing's advice and created a new post so you would get the points.


No prob...  It's related to the previous info
so hopefully the extra facts will be helpful
to future viewers of this file size limit paq!
I know that the partition size limit under FAT32 is 2 terrabytes.  What I DON'T know is the maximum size Windows 98Second Edition can handle.  Do you?
Now there's a simple question with a complicated answer if I ever saw one.

Originally, Windows 98SE was limited to 64GB, but this was not an OS limitation at all. The limit is caused by the disk tools shipped with Win98SE.

FDISK.EXE shipping with Win98 had internal limitations in the coding that, if you had a drive over 64GB, would display the drive size minus 64GB.

You can get an updated version of FDISK here:

This increases FDISK's support up to the limit where you need to use LBA (Large Block Addressing) mode, 137 GB.

Scandisk and Defrag also does not work if you have a partition over 127GB.


Boot Partition should NOT be over 127 GB, but Win98SE can use partitions up to the FAT32 barrier if you use third party tools for disk management.
Thanks SunKing.
That's exactly what I needed.  I split the 160GB partition that was trashing both hdd's in two, and it fixed the problem.
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