The term 1.44Mb floppy disc is a bastard admixture of division by powers of ten with division by powers of two that should never have seen the light of day.
A high capacity 90mm floppy disc that is low-level formatted in the standard manner has 2 sides, 80 tracks, and 18 sectors per track. There are thus 2880 sectors on the disc. Each sector holds 0.5KiB, which is 512 bytes, meaning that the formatted data capacity of the disc is 1440KiB, which is 1474560 bytes.
1474560 divided by 1024 squared is 1.40635. The formatted data capacity of a 90mm high capacity floppy disc in megabinarybytes is thus (approximately) 1.41MiB.
1474560 divided by 1000 squared is 1.47456. The formatted data capacity of a 90mm high capacity floppy disc in megabytes is thus (approximately) 1.47MB.