Mathematics in Markdown

Use ordinary Markdown for explanation and LaTeX for notation. This reference explains what each delimiter, backslash, brace, operator, and row marker does so a first-time writer can build formulas safely.

MarkIOY Team · August 12, 2026 · 22 min read

The two delimiters

Markdown itself does not define mathematics; a math-enabled renderer passes the text between delimiters to a LaTeX math renderer. Most use dollar signs. The delimiters are not part of the equation: they tell the renderer where math begins and ends.

A common beginner mistake is writing currency beside a formula. In normal prose, escape a literal dollar as \$5. Do not put spaces just inside a delimiter pair such as $ x $; some renderers accept it, others do not. If a formula is long, use a display block rather than forcing it into a sentence.

Inline example

The quadratic formula gives $x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$.

Keep inline math short. A reader should be able to continue the sentence after it without losing the grammar. The \frac command begins with a backslash, then takes two brace groups: the first is the numerator and the second is the denominator.

Display example

$$
E = mc^2
$$

Leave a blank line before and after a display equation. This is clearer in raw Markdown and avoids edge cases in renderers that require the delimiters to be on their own lines. Read E = mc^2 character by character: = means equals, plain letters are variables, and ^ attaches the next item as a superscript.

Common LaTeX building blocks

LaTeX is built from ordinary characters, commands, and groups. A backslash \ starts a named command; braces { } keep several characters together as one argument; a caret ^ makes a superscript; an underscore _ makes a subscript.

For a geometric series with ratio $r$, where $|r| < 1$:

$$
\sum_{n=0}^{\infty} ar^n = \frac{a}{1-r}
$$

Use braces whenever a superscript or subscript contains more than one character. x^10 means “x to the first power, then 0”; x^{10} means “x to the tenth power.” For a function, write \sin, \cos, \log, or \exp, rather than sin, so the renderer knows it is one operator rather than three multiplied variables.

Complex equations: alignment, cases, and matrices

For multi-line derivations, use an aligned environment inside a display block. \begin{aligned} opens the environment and \end{aligned} closes it. The ampersand & marks the vertical alignment point; the double backslash \\ ends one row and begins the next. Because every marker matters, edit these structures like code.

$$
\begin{aligned}
f(x) &= x^2 + 2x + 1 \\
+     &= (x + 1)^2
\end{aligned}
$$

Piecewise definition

$$
f(x) =
\begin{cases}
x^2, & x \ge 0 \\
+-x,  & x < 0
\end{cases}
$$

In cases, each row has two columns separated by &: the value first, then its condition. A row ends with \\. Commands such as \ge and \lt express ≥ and <; never rely on visual spacing to communicate a condition.

Matrix and vector

$$
A = \begin{bmatrix}
1 & 2 \\
+3 & 4
\end{bmatrix}
\qquad
\vec{v} = \begin{bmatrix} x \\ y \end{bmatrix}
$$

In a matrix, & separates columns and \\ separates rows. bmatrix adds square brackets; pmatrix adds round brackets; vmatrix adds vertical bars. \qquad is wide visual spacing and should be used sparingly; it is not a substitute for mathematical structure. These environments are easy to damage when editing visually, so write in source mode, render, then make one small correction at a time.

Compatibility and best practices

Confirm the renderer before choosing syntax

Dollar delimiters are common, but not universal. GitHub Markdown, static-site generators, note apps, and chat tools each enable mathematics differently. Some require an extension; some use \( ... \) and \[ ... \] instead. Preview in the destination, not only in the authoring tool. KaTeX deliberately supports a practical subset of full LaTeX, so a command that works in a desktop TeX compiler may still be unavailable on the web.

Keep prose outside the formula

Explain what every displayed equation is for immediately before or after it. A formula without variables, units, assumptions, or a conclusion is difficult for collaborators and AI systems to interpret correctly.

Use semantic LaTeX, not visual spacing tricks

Prefer \frac, \sum, \text{where}, and environments such as aligned to manually aligned spaces. Semantic structure is more robust across screen sizes and easier to revise. Do not use ^, _, &, or \\ as decoration: each has a specific grammar role.

Escape Markdown only when necessary

Keep formulas out of link labels and emphasis markers. If literal dollar signs appear in normal text, escape them as \$. Put an equation in its own display block rather than trying to nest it in a complicated list, table, or quote. If a preview fails, first check matching delimiters, matching braces, command spelling after \, then row markers in that order.

Make equations accessible

Use descriptive sentences, define symbols nearby, and do not encode the only explanation in an image. If you export a document, inspect the output: a formula that looks correct in a browser may not be selectable or readable in another format.