The amount of storage, either logical or physical, required for a file or dataset.
File size is a measure of the amount of storage, either logical or physical, required for a file or dataset.
The logical amount corresponds to the space required to represent all the information in the file. The physical amount is the space actually occupied on a storage device. The physical size may differ from the logical size due to the type of compression techniques employed and the file system used.
Size is most commonly measured in terms of (8-bit) bytes. The SI prefix denotes the factor of which the amount should be multiplied (eg. Kilo = 1000 or 1024, Mega = 1,000,000 or 2^20, etc). Some of the most typically used units of file size are:
- One Byte = 8 bits
- One Kilobyte = 1 KB = 1,024 = 2^10 bytes
- One Megabyte = 1 MB = 1,048,576 = 2^20 bytes
- One Gigabyte = 1 GB = 1,073,741,824 = 2^30 bytes
- One Terabyte = 1 TB = 1,099,511,627,776 = 2^40 bytes
Information describing file sizes in greater detail is available at:
