File size measures the size of a computerfile. Typically it is measured in bytes with an SIprefix. The actual amount of disk space consumed by the file depends on the file system. The maximum file size a file system supports depends on the number of bits reserved to store size information and the total size of the file system. For example, with FAT16X, the size of one file cannot be equal or larger than 4 GiB. Some common file size units are: