An individual subscription is only A$60 per year

Group and student discounts may apply

*Australian manual of scientific style *Start communicating effectively

Use the same rules – for abbreviations, and for words versus numerals – as for scientific units.

12 MB 16 GB 23 Kibits/s

[Computer memory is usually expressed in gigabytes.]

This section covers:

The basic unit of data is the binary bit (symbol: bit), which can take on a value of 1 or 0. A byte (B) consists of 8 bits.

According to the International System of Quantities, a kilobyte is 1,000 bytes. The recommended symbol is kB. This usage agrees with the International System of Units, which is the modern form of metric measurement. The same is true of *mega- *(M), *giga-* (G) and other prefixes.

Because binary arithmetic is so important in computing, kilobytes were traditionally (and continue to be) taken by some companies and users as 2^{10} = 1,024 bytes. This is now more properly referred to as a kibibyte (*KiB *– note the capital K), where the *bi* denotes the binary origin of the value. Similarly, we have mebibytes (MiB), gibibytes (GiB) and so on.

When transferring data (eg over the internet), speeds are typically expressed in bits per second. The unit should in general be written *bit/s*. The form *bps* is widely used in material for a general readership, where its similarity to *kph* (kilometres per hour) may be an aid to understanding. In more formal writing, *bits/s* is preferred, because it uses the correct unit symbol (*bit*) and is more in keeping with the standard way of writing units of measure:

The NBN typically delivers data rates above 40 Mbps.

or (more correctly)

The NBN typically delivers data rates above 40 Mbit/s.

Unit |
Symbol |
Definition |
---|---|---|

bit |
bit |
A single binary data element; 1 or 0 |

byte |
B |
8 bits |

kilobyte |
kB |
1,000 B |

megabyte |
MB |
1,000 kB |

gigabyte |
GB |
1,000 MB |

terabyte |
TB |
1,000 GB |

petabyte |
PB |
1,000 TB |

kilobit |
kbit |
1,000 bits |

kilobits per second |
kbit/s |
1,000 bits per second |

megabits per second |
Mbit/s |
1,000 kbits per second |

kibibyte |
KiB |
1,024 B |

mebibyte |
MiB |
1,024 KiB |

gibibyte |
GiB |
1,024 MiB |

tebibyte |
TiB |
1,024 GiB |

pebibyte |
PiB |
1,024 TiB |

kibibit |
Kibit |
1,024 bits |

kibibits per second |
Kibit/s |
1,024 bits per second |

mebibits per second |
Mibit/s |
1,024 Kibit per second |

Computers are coordinated by an internal clock. The computer state is updated each time the clock ticks. So, the faster the clock, the faster the computer.

Frequencies are expressed in cycles per second, or hertz (Hz). Hertz is a measure derived from the International System of Units.