Mebibyte (MiB)
Modern equivalent
1,048,576 bytes = 1.049 megabytes
Exactly 1,048,576 bytes, being two to the power of twenty, and the binary counterpart to the decimal megabyte.
At the mebibyte the binary and decimal figures have drifted nearly five per cent apart, which is where the discrepancy first becomes noticeable in everyday use. The 1.44 MB floppy disk is the classic monument to the confusion: its capacity was neither 1.44 decimal megabytes nor 1.44 mebibytes but 1,474,560 bytes, arrived at by multiplying 1,440 kibibytes by a decimal thousand. Two incompatible conventions applied to the same number, on a product sold in the millions.