About capacity: 4GB = approximately 3.6GB-3.9GB 8GB = approximately 7.4GB-7.8GB 16GB = approximately 14.2GB-15GB 32GB = approximately 28GB-30GB 64GB = approximately 58GB-60GB 128GB = approximately 110GB-120GB 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.