Ring in LaTeX (\mathring{x})

Where it is used

Places a small ring above a symbol, used for interiors of sets and some unit symbols.

Topology sometimes writes \mathring{A} for the interior of A (an alternative to A^\circ or \operatorname{int} A), and differential geometry uses it for traceless or reference quantities. For the angstrom symbol in text use \AA, and for the Scandinavian letter å use \aa; \mathring is only for math mode. It differs from a superscript \circ, which sits to the upper right rather than centered above. The ring is sized for a single letter. Over the letters i and j, use \imath or \jmath so the ring replaces the dot.

Minimal compilable example

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

\documentclass{article}
\begin{document}
Ring: $\mathring{x}$

\[ \mathring{A} \subseteq A \subseteq \overline{A} \]
\end{document}

Related symbols

• Overbrace\overbrace{x+y}^{\text{sum}}
• Check\check{x}
• Underbrace\underbrace{x+y}_{\text{sum}}
• Breve\breve{x}
• Cancel\cancel{x}
• Grave\grave{x}

Frequently asked questions

How do I write Ring in LaTeX?

Type \mathring{x} in math mode, for example $\mathring{A} \subseteq A \subseteq \overline{A}$. It works in plain LaTeX without loading any package.

Which package do I need for \mathring{x}?

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

Can I use \mathring{x} in text mode, or only in math mode?

Only in math mode. Outside $...$ LaTeX stops with "Missing $ inserted", so write $\mathring{x}$ in running text.