My 200 GB hard drive is only regocnized as 186 GB. Why is the capacity of my hard drive being reported less than the full size of the drive reported on the box?
The difference is due to two different number systems used to express units of storage capacity, binary and decimal. The hard drive capacity reported on the box by the hard drive manufacturer is based in decimal. Windows reports capacity based in binary. The following is an excerpt from a Seagate Knowledge Base article: There are two different number systems which are used to express units of storage capacity; binary, which says that a kilobyte is equal to 1024 bytes, and decimal, which says that a kilobyte is equal to 1000 bytes. The storage industry standard is to display capacity in decimal. Even though in binary you have more bytes, the decimal representation of a Gbyte shows greater capacity. The following table is an excerpt from a Western Digital Knowledge Base article which shows differences in capacity reported for various hard drive sizes: Drive Size in GB Approximate Total Bytes Decimal Capacity (bytes/1,000,000,000) Approximate Binary Capacity (bytes/1,073,724,841) 10 GB 10
