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Data storage

Storage capacity and file size

Storage capacities and file sizes are measured from lowest to highest in:

  • bits
  • bytes
  • kilobytes
  • megabytes
  • gigabytes
  • terabytes

An operating system [operating system: an interface between hardware, eg a computer, and the user ] abbreviates these measurements, eg 1 megabyte becomes 1MB (megabyte).

Relationship between measurements

The table below outlines the relationship between bits (smallest) and terabytes (largest). Read each row of the table from left to right:

Relationship between measurement

SizeEqual to
8 bits1 byte
1024 bytes1 kilobyte
1024 kilobytes1 megabyte
1024 megabytes1 gigabyte
1024 gigabytes1 terabyte

The size of a file and a storage device's capacity will always be written in its simplest form. For example, an operating system would report a 1 terabyte hard disk's [hard disk: a device used to store vast amounts of data, the data is stored on a disk ] size as 1TB not as 1024GB, although both are correct.

Example file sizes

The table below lists files commonly found on a computer and their typical file size (compressed):


FileFile size

A file’s size can be influenced by a number of factors but ultimately the more information a file stores, the larger it will be.

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