Computer storage manufacturers use a different measuring system to the one computers use. The units on the packaging are in decimal, but computers use binary.
For example, the packaging says 1 Terabyte (1000^4), but the computer needs 1 Tebibyte (1024^4) to provide the capacity people initially think it should.
Let’s convert 1 TB into 1 TiB
| Units | Calculations |
| 1 TB | * 1000 |
| 1,000 GB | * 1000 |
| 1,000,000 MB | * 1000 |
| 1,000,000,000 KB | * 1000 |
| 1,000,000,000,000 B | / 1024 |
| 976,562,500 KiB | / 1024 |
| 953,674.3 MiB | / 1024 |
| 931.3 GiB | / 1024 |
Here is a shorter version of this equation
1000^4 / 1024^3 ≈ 931.3 GiB
Why Is This the Case?
There are two standards. IEC’s and JEDEC’s. The former is used by computer scientists; the latter is used by businesses and virtually anyone else. People are just ignoring the IEC guidance.
Take a look at this quote from Google Cloud’s pricing
“Storage usage is calculated in gigabytes (GB), where 1 GB is 2^30 bytes. This unit of measurement is also known as a gibibyte (GiB). Similarly, 1 TB is 2^40 bytes (1,024 GB).”