With FAT16 the maximum partition size is 2GB when your maximum cluster size is 32K.
This is calculated by multiplying the number of addressable units by the cluster size.
(216 Allocation units) * (215 bytes/cluster) = 2 GiB
However with FAT32, when I do the same calculation I get a much larger number than the 8 TiB maximum when using 232 clusters.
(232 Allocation units) * (cluster size)
If I use a cluster size of 512 bytes, I've already arrived at 2 TiB.
In an XP TechNet article, Microsoft says
The maximum possible number of clusters on a FAT32 volume is 268,435,445, and there is a maximum of 32 KB per cluster, along with the space required for the file allocation table (FAT).
This puts the maximum cluster size at 228 - 11.
Why is the maximum number of clusters in FAT32 228-11 and not 232, given that it was 216 in FAT16?