> For the complete documentation index, see [llms.txt](https://overleaf-pro.ayaka.space/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://overleaf-pro.ayaka.space/latex/latex-errors/11-latex-error-mathrm-allowed-only-in-math-mode.md).

# LaTeX Error: \mathrm allowed only in math mode

This error appears when we use a font in text mode which is only allowed in math mode. When using such fonts, ensure to include them inside dollar signs as `$...$`. To learn more about mathematical fonts, feel free to check out our [documentation](/latex/mathematics/12-mathematical-fonts.md). A list of such fonts, with their corresponding packages is shown below

|                  |                                                                                                                                                                                                                                                              |
| ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| \mathnormal{...} | This is the standard italic font in math italic font. `$\mathnormal{Hello world}$` will give the same result as `$Hello world$`.                                                                                                                             |
| \mathrm{...}     | This is the standard text Roman font.                                                                                                                                                                                                                        |
| \mathbf{...}     | This gives bold letters in math mode.                                                                                                                                                                                                                        |
| \mathcal{...}    | This is a special calligraphic font in math mode. It can be used for uppercase letters only, such as for identifying real numbers. `\mathcal{R}` will give ℝ.                                                                                                |
| \mathsf{...}     | This gives sans serif letters in math mode.                                                                                                                                                                                                                  |
| \mathit{...}     | This will give text italic letters. These can be different to math italic letters depending on the specific class used.                                                                                                                                      |
| \mathtt{...}     | This gives upright letters from the typewriter type font used.                                                                                                                                                                                               |
| \mathbb{...}     | This provides a "blackboard bold" font for uppercase letters. The [**`amsfonts`**](https://www.ctan.org/pkg/amsfonts?lang=en) package or equivalently The [**`amssymb`**](https://www.ctan.org/pkg/amssymb?lang=en) package must be loaded to use this font. |
| \mathfrak{...}   | This provides Gothic letters in both upper and lower case. The [**`amsfonts`**](https://www.ctan.org/pkg/amsfonts?lang=en) package or equivalently The [**`amssymb`**](https://www.ctan.org/pkg/amssymb?lang=en) package must be loaded to use this font.    |
| euscript         | The [**`euscript`**](http://tug.ctan.org/fonts/amsfonts/doc/euscript.pdf) package provides us with another calligraphic alphabet called Euler script.                                                                                                        |

**Text equivalents of the above math fonts:**

| Math mode font   | Text Equivalent               |
| ---------------- | ----------------------------- |
| \mathnormal{...} | \textit{...}.                 |
| \mathrm{...}     | \text{...}                    |
| \mathbf{...}     | \textbf{...}.                 |
| \mathcal{...}    | No equivalent text mode font. |
| \mathsf{...}     | \textsf{...}.                 |


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