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.
8GB=approximately 7.4GB-7.8GB
16GB=approximately 14GB-15GB
32GB=approximately 28GB-30GB
64GB=approximately 58GB-59GB
128GB=approximately 110GB-120GB
256GB=approximately 230GB-240GB
This is the calculation difference between the manufacturer and our PC, please Google 'Memory card capacity' to get more information.