Answer to Question #4575 in Math for Rizvan

Floppy disks often have two capacity specifications; they are often
quoted with both their unformatted capacity, and their formatted
capacity. Since the disk is useless unless it is formatted the
unformatted capacity means basically nothing. The formatted capacity is
the true maximum capacity of the disk. Usually, the formatted capacity
is about three-quarters the unformatted capacity.

Even the formatted capacity, however, doesn't show the true amount of
space available for user files, because a certain amount of overhead is
taken up for FAT file structures. This is true of hard disks as well, of
course, although as a percentage more of the floppy is taken up by this
information than a hard disk is. The amount of space remaining after
these structures are placed on the disk is the true usable capacity of
the floppy.

Note also that the "decimal vs. binary" measurements problem is in play
again with the terminology used to specify floppy capacity. In fact, the
terms are not even consistent in and of themselves. For example, a 1.44
MB floppy disk takes its name from the fact that the disk has 2,880
sectors, and each sector is 0.5 KB; 0.5 times 2,880 is 1,440, so the
1.44 is a decimal measure. But, each sector is really 512 bytes, so the
0.5 KB is a binary measure. As a result the "1.44" is a mixed measurement; the true raw formatted capacity is either 1.41 MB (binary)
or 1.47 MB (decimal), and not 1.44 MB at all