The drive says it is a 160 GB but after formatting it shows that only 149 GB is available. Why?
The unformatted capacity of any hard drive will always be greater than the formatted capacity. In the hard drive industry the partitioned size will be less than the printed capacity on the label. This is consistent whether it is Western Digital, Seagate, Samsung, etc. A 160GB hard drive will have a formatted capacity of approximately 149-150GB. This is due to the fact that computers calculate capacity based on 1024 bytes/kilobyte, while the hard drive calculation is based on 1000 instead of 1024. Hard drive manufacturers define a megabyte as 1,000,000 bytes and a gigabyte as 1,000,000,000 bytes, which is a decimal (base 10) measurement. Computers define a megabyte as 1,048,576 bytes and a gigabyte as 1,073,741,824 bytes. These are binary (base 2) measurements. This is why the two different industries will report different capacities for the same drive. The number of bytes is the same, but a different number of bytes is used to make a megabyte and a gigabyte.
The unformatted capacity of any hard drive will always be greater than the formatted capacity. In the hard drive industry the partitioned size will be less than the printed capacity on the label. This is consistent whether it is Western Digital, Seagate, Samsung, etc. A 160GB hard drive will have a formatted capacity of approximately 149-150GB. This is due to the fact that computers calculate capacity based on 1024 bytes/kilobyte, while the hard drive calculation is based on 1000 instead of 1024. Hard drive manufacturers define a megabyte as 1,000,000 bytes and a gigabyte as 1,000,000,000 bytes, which is a decimal (base 10) measurement. Computers define a megabyte as 1,048,576 bytes and a gigabyte as 1,073,741,824 bytes. These are binary (base 2) measurements. This is why the two different industries will report different capacities for the same drive. The number of bytes is the same, but a different number of bytes is used to make a megabyte and a gigabyte.
