The actual capacity of USB memory stick is less than the named capacity. There are two causes. The first cause is between the definition of GB, MB, KB between the computer memory system and the memory manufacturing industry. For the computer system, it defines 1GB=1024MB, 1MB=1024KB, 1KB=1026B. While with memory manufacturers, it defines 1GB=1000MB, 1MB=1000KB, 1KB=1000B.
The second cause is part of the capacity is used for functions like format. Thus it’s not for storage.
In short, the real capacity for USB flash drive is about 93% of its named capacity.
Also a lot of consumers wonder about the data amount they could put onto a USB thumb drive when they have one at hand or before they make the purchase of the USB pendrive. It is difficult of calculate if you know the size of file/ data you ‘d like to save on the USB stick. The below chart is shown for reference based on the most common file size.