Mu in LaTeX (\mu)

Where it is used

Lowercase Greek mu, standard for the mean, measures, friction coefficients, and the micro prefix.

Probability writes the mean as \mu = E[X], so a normal distribution is \mathcal{N}(\mu, \sigma^2). Measure theory uses \mu for a measure, and physics uses it for the coefficient of friction, magnetic permeability \mu_0, and reduced mass. As a unit prefix in \mu m or \mu s it renders in math italic, whereas typographic standards ask for an upright micro sign, and wrapping it in \mathrm does not change a Greek letter's shape. Optimization uses \mu for barrier parameters in interior-point methods.

Also listed under: Probability & Statistics, Units & Measurements, Optimization

Minimal compilable example

Paste this into an empty .tex file and compile it with pdfLaTeX, XeLaTeX or LuaLaTeX.

\documentclass{article}
\begin{document}
Mu: $\mu$

\[ f(x) = \frac{1}{\sigma\sqrt{2\pi}} e^{-\frac{(x-\mu)^2}{2\sigma^2}} \]
\end{document}

Related symbols

• Nu\nu
• Lambda (Upper)\Lambda
• Xi\xi
• Lambda\lambda
• Xi (Upper)\Xi
• Kappa\kappa

Frequently asked questions

How do I write Mu in LaTeX?

Type \mu in math mode, for example $f(x) = \frac{1}{\sigma\sqrt{2\pi}} e^{-\frac{(x-\mu)^2}{2\sigma^2}}$. It works in plain LaTeX without loading any package.

Which package do I need for \mu?

None. \mu is part of standard LaTeX, so it compiles with nothing in the preamble but the document class.

Can I use \mu in text mode, or only in math mode?

Only in math mode. Outside $...$ LaTeX stops with "Missing $ inserted", so write $\mu$ in running text. If you only need the glyph in text, paste the Unicode character μ instead (with XeLaTeX or LuaLaTeX and a font that has it).