Hard disk/flash memory factory for all storage devices are using decimal arithmetic: 1MB=1000KB, 1G=1000MB calculated, but the operating system is using binary arithmetic: 1MB=1024KB, 1GB=1024MB. So there are some differences between display capacity and nominal capacity of hard disk/flash memory products. However, this is allowed to exist from industry standard. The actual capacity calculation:total storage x0.93, for examples:

8G=about 7.5GB, 16GB=about 14GB, 32GB=about 29GB,  64GB=about 57GB,120GB=about 111GB,  128GB=about 119GB,    256GB=about 238GB,  480GB=about 447GB,    500GB=about 465GB,  512GB=about 476GB,  1TB=about 930GB,  2TB=about 1862GB,3TB=about 2793GB,   4TB=about 3724GB