# Directory `macros/latex/contrib/siunitx`

# siunitx - A comprehensive (SI) units package

Physical quantities have both numbers and units, and each physical quantity should be expressed as the product of a number and a unit. Typesetting physical quantities requires care to ensure that the combined mathematical meaning of the number-unit combination is clear. In particular, the SI units system lays down a consistent set of units with rules on how these are to be used. However, different countries and publishers have differing conventions on the exact appearance of numbers (and units). The `siunitx`

package provides a set of tools for authors to typeset quantities in a consistent way. The package has an extended set of configuration options which make it possible to follow varying typographic conventions with the same input syntax. The package includes automated processing of numbers and units, and the ability to control tabular alignment of numbers.

Download the contents of this package in one zip archive (2.1M).

## siunitx – A comprehensive (SI) units package

Typesetting values with units requires care to ensure that the combined mathematical meaning of the value plus unit combination is clear. In particular, the SI units system lays down a consistent set of units with rules on how they are to be used. However, different countries and publishers have differing conventions on the exact appearance of numbers (and units). A number of LaTeX packages have been developed to provide consistent application of the various rules: SIunits, sistyle, unitsdef and units are the leading examples. The numprint package provides a large number of number-related functions, while dcolumn and rccol provide tools for typesetting tabular numbers.

The siunitx package takes the best from the existing packages, and adds new features and a consistent interface. A number of new ideas have been incorporated, to fill gaps in the existing provision. The package also provides backward-compatibility with SIunits, sistyle, unitsdef and units. The aim is to have one package to handle all of the possible unit-related needs of LaTeX users.

The package relies on LaTeX 3 support from the l3kernel and l3packages bundles.

Package | siunitx |

Home page | https://www.texdev.net |

Bug tracker | https://github.com/josephwright/siunitx/issues |

Repository | https://github.com/josephwright/siunitx |

Version | 3.0.31 2021-09-22 |

Licenses | The LaTeX Project Public License 1.3c |

Copyright | 2008–2021 Joseph Wright |

Maintainer | Joseph Wright |

TDS archive | `siunitx.tds.zip` |

Contained in | TeX Live as siunitx MiKTeX as siunitx |

Topics | Scientific docs Experimental LaTeX3 Units |