siunitx in Scissor LaTeX
The siunitx package does not work in Scissor LaTeX. \SI, \si, \qty, \unit and \num are unknown: in text the number stays but the unit disappears (with a Problems note), and in a formula the whole formula turns red; write units with \mathrm and a thin space \, instead.
What the package does
siunitx typesets numbers and units consistently. You write \SI{44}{\kilo\metre} (or \qty{44}{\km} in version 3) and get the number, a thin space and an upright unit. It also formats long numbers, aligns numbers in table columns, and prints ranges and lists.
What works here
| Command | In Scissor LaTeX | What you see |
|---|---|---|
\SI{44}{\kilo\metre}, \qty{44}{\km} in text | Not supported | "44": the number stays, the unit is lost. The Problems tab lists the skipped commands. |
\si{\metre\per\second}, \unit{...} in text | Not supported | Nothing: the unit is lost. |
\num{12345.6} in text | Not supported | "12345.6", without digit grouping. |
Any of them inside $...$ or \[...\] | Not supported | The whole formula is shown in red. |
\sisetup{...}, column type S | Not supported | \sisetup is skipped silently. An S column is read as a centred column, so numbers are not aligned at the decimal point. |
Examples
In text, the number survives but the unit does not:
\SI in text loses the unit
The track is \SI{44}{\kilo\metre} long.Problems tab: Skipped 3 unknown commands: \SI, \kilo, \metre
In a formula, the whole formula turns red:
\SI in a formula shows it in red
The speed is $v = \SI{12}{\metre\per\second}$.Shown in red: the formula cannot be read, so its source is shown instead.
Write units by hand. A thin space \, separates number and unit, and \mathrm keeps the unit upright:
Numbers and units written by hand
The track is $44\,\mathrm{km}$ long, and John Doe runs it at
$3.5\,\mathrm{m\,s^{-1}}$. The water is at $20\,^{\circ}\mathrm{C}$
(or 20\,\textdegree C in text), the resistor has $12\,\mathrm{k\Omega}$,
the hair is $5\,\mu\mathrm{m}$ thick, and the sample weighs
$1.2 \times 10^{3}\,\mathrm{kg}$. Prices rose by 10\,\%.
If you write many units, short commands save typing:
Your own unit commands
\documentclass{article}
\newcommand{\un}[1]{\,\mathrm{#1}}
\newcommand{\celsius}{\,^{\circ}\mathrm{C}}
\begin{document}
Erika Mustermann measured $44\un{mm}$ at $21\celsius$,
and a flow of $0.8\un{L\,min^{-1}}$.
\end{document}Compatibility
- From a TeX installation to here: text keeps the numbers but loses the units, and formulas with
siunitxcommands turn red. Replace them with\,\mathrm{...}as above. - From here to a TeX installation: units written with
\mathrmand\,compile everywhere and look the same.
The full manual is on CTAN: ctan.org/pkg/siunitx. See also Math in LaTeX: the basics.
See also Math basics, Tables and physics.
Questions and answers
How do I write degrees Celsius without siunitx?
In a formula write 20\,^{\circ}\mathrm{C}; in text write 20\,\textdegree C. Both work here and in a TeX installation.
Why is there a space between the number and the unit?
Units are separated from numbers by a thin space in most style guides. \, gives that space and keeps the number and unit on one line.
Every example on this page is typeset by Scissor LaTeX when the site is built. Last updated 2026-11-06.