Harddisk Size

Hard Disk Size Calculation
capacity = cpd * hpc * tph * spt * bps = cpd * hpc * spt * 512

capacity       : harddisk capacity in bytes cpd            : cylinders per disk hpc            : heads per cylinder tph            : tracks per head (= 1) spt            : sectors per track bps            : bytes per sector (= 512)

Example
If a harddisk has 16,384 cylinders per disk, 80 heads per cylinders, and 63 sectors per track, it has the capacity:

16,384 * 80 * 63 * 512 = 42,278,584,320 bytes = 39 GB