Usb Capacity :
Capacity flash memory products are usually shipped in accordance with 1MB = 1000KB, 1G = 1000MB computing,but the operating system
using binary arithmetic 1MB = 1024KB, 1GB = 1024MB,so there are some differences between the display capacity and standard
capacity memory products. Thus, the real capacity is
4GB = approximately 3.6GB-3.8GB
8GB = approximately 7.4GB-7.6GB
16GB = approximately 14.4GB-14.8GB
32GB = approximately 28.5GB-30GB
64GB = approximately 58.5GB-60GB
128GB = approximately 110GB-124G
Vendors are using Flash memory decimal arithmetic: 1 MB = 1000KB, 1G = 1000 MB
Calculated, operating system with binary arithmetic: 1 MB = 1024KB, 1 GB = 1024 MB;
So there are some differences between display capacity and nominal capacity of flash memory products
There is calculation difference between manufacturer and your PC, please Google 'Memory card capacity' to get more information.