Sometimes, data storage isn’t all that appears to be. You may have noticed that volume capacities reported by ADM appear lower than the capacity indicated on hard drive labels and advertisements. This is because hard drive manufacturers use decimal measurements to calculate storage space, that is measurements use units based on a power of 10, (1 TB = 1000 GB) while some operating systems measure data storage with units based on a power of 2 (1 TB = 1024 GB). Apple devices express data storage on units based on the power of 10, while Windows, despite using decimal prefixes, measures with units based on the power of 2 measurements and this causes discrepancies in the expression of data storage. Numerous other operating systems like most Linux distributions use binary prefixes; kibi, mebi, gibi… instead. These are equal to expressions based on the power of 2.
Conversion formula:
Decimal capacity / 1,048,576 = Binary MB capacity
Decimal capacity / 1,073,741,824 = Binary GB capacity
Decimal capacity / 1,099,511,627,776 = Binary TB capacity
Conversion example:
A 500 GB hard drive is approximately 500,000,000,000 bytes (500 x 1,000,000,000).
The binary GB calculation is 500,000,000,000 / 1,073,741,824 = 465.661287308, so a 500 GB hard drive will appear as 465 GB on a Windows operating system.
A 500 GiB volume on most Linux distributions is equal to a 500 GB volume on Windows.
Comparison of common hard drive capacities:
