The LaTeX command for mathbb R (ℝ) is \mathbb{R} (real numbers).
\mathbb{R}Writing a paper? The table generator and the BibTeX cleaner are one click away, no account.
| Command | Package | Use it when |
|---|---|---|
\mathbb{R} recommended | amssymb | The set of real numbers, blackboard bold. |
\mathbb{R}^n | amssymb | n-dimensional real space. |
\mathbb{R}_{>0} | amssymb | The positive reals. |
\mathbf{R} | none | Bold R, the older style found in many textbooks; needs no package. |
Write \mathbb{R} inside math mode, that is between $…$ for inline math or in a \[ … \] or equation block for display math. This symbol needs the amssymb package, so add \usepackage{amssymb} to your preamble.
$f\colon \mathbb{R}^n \to \mathbb{R}$Open this example in the live preview: it renders as you type, with no compiler and no signup.
\mathbb{N} (ℕ): natural numbers\mathcal{N} (𝒩): normal / Gaussian distribution\mathds{1} (𝟙): indicator function / characteristic function\emptyset\varnothing\mathbb{N}\mathbb{Z}\mathbb{Q}\mathbb{C}\mathbb{F}^\complement\bigcap\bigcup\bigsqcup\uplus\biguplus\mathcal{P}Set symbols in LaTeX: the full table or search all 350+ LaTeX symbols.
Use \mathbb{R} in math mode after adding \usepackage{amssymb} to your preamble. For example, $f\colon \mathbb{R}^n \to \mathbb{R}$.
It comes from the amssymb package: add \usepackage{amssymb} to your preamble.
\mathbb is not built in: load amssymb (or amsfonts). It also has capitals only, so \mathbb{r} prints an unrelated symbol.