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 abbreviates these measurements, eg 1 megabyte becomes 1MB (megabyte).

Relationship between measurements

The table below outlines the relationship between bits (smallest) and terabytes (largest):

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 size as 1TB not as 1024 GB, 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
Photo3MB
Song5MB
Film1-1.5GB

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.