Double Integral in LaTeX (\iint)

Where it is used

Double integral sign for integrating a function of two variables over a planar region.

A double integral appears whenever you integrate over an area, as in \iint_D f(x,y)\,dA for mass, for probability over a joint density, or for flux through a surface. Typing \int\int by hand produces two signs with too much space between them; \iint kerns them into a single tight pair. Put the region as one subscript, \iint_{D}, rather than splitting bounds across both signs. If you need separate bounds for each variable, write \int_a^b\!\int_c^d instead, since the combined command only takes one set of limits. The \! negative thin space keeps such hand-built pairs from drifting apart.

Minimal compilable example

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

\documentclass{article}
\usepackage{amsmath}
\begin{document}
Double Integral: $\iint$

\[ \iint_D (x^2 + y^2)\,dA \]
\end{document}

Related symbols

• Triple Integral\iiint
• Integral\int_{a}^{b}
• Contour Integral\oint
• Integral\int
• Derivative\frac{d}{dx}
• Nabla\nabla

Frequently asked questions

How do I write Double Integral in LaTeX?

Type \iint in math mode, for example $\iint_D (x^2 + y^2)\,dA$. Load amsmath first with \usepackage{amsmath}.

Which package do I need for \iint?

\iint needs amsmath: add \usepackage{amsmath} to your preamble before the document starts.

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

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