LaTeX Subscript & Superscript Tutorial - Complete Guide

Master LaTeX subscript and superscript notation for mathematical expressions, scientific notation, and technical documentation. Whether you’re writing research papers, chemical formulas, tensors, or complex equations, this comprehensive guide covers everything from basic subscript syntax to advanced techniques for professional mathematical typesetting.

Quick start: Use _ for subscripts and ^ for superscripts. For multiple characters, enclose in braces: x_{12} and x^{2n}.Prerequisites: Basic LaTeX knowledge. For math mode basics, see Mathematical Expressions.Last updated: January 2026 | Reading time: 12 min | Difficulty: Beginner to Intermediate

What You’ll Learn

✅ Basic LaTeX subscript and superscript syntax for mathematical notation
✅ Multiple character subscripts and compound superscript expressions
✅ Special cases (limits, operators, tensor notation)
✅ Chemical formula subscript notation and isotopes
✅ Advanced subscript positioning and formatting techniques
✅ Common subscript errors and how to fix them
✅ Best practices for readable mathematical notation

Frequently Asked Questions

What is the difference between subscripts and superscripts in LaTeX?

In LaTeX, subscripts are notations placed below the baseline using the underscore character (_), commonly used for indices and chemical formulas. Superscripts are placed above the baseline using the caret character (^), typically for exponents and powers. Both are essential for mathematical and scientific notation in professional documents.Quick Example:

Subscript: x_1 renders as x₁
Superscript: x^2 renders as x²

How do I write multiple character subscripts in LaTeX?

Always use braces {} to group multiple characters in a LaTeX subscript or superscript. Without braces, only the first character becomes a subscript.Correct subscript syntax:

x_{12}      % Both 1 and 2 are subscript
x_{n+1}     % Entire expression is subscript

Wrong syntax:

x_12        % Only 1 is subscript (renders as x₁2)

This is one of the most common subscript errors in LaTeX.

Why do I get a 'Double subscript' error in LaTeX?

The “Double subscript” error occurs when you try to apply two subscripts to the same variable without proper grouping:

x_a_b       % ERROR: Double subscript

Solutions:

Use nested braces if one subscript depends on another:

x_{a_b}     % Correct: a has subscript b, all subscript to x

Or separate them with an empty group:

x_a{}_{b}   % Correct: separate subscripts

How do I use subscripts in chemical formulas?

For chemical formula subscript notation, enclose the formula in \mathrm{} and use subscripts for atom counts:

$\mathrm{H_2O}$         % Water
$\mathrm{SO_4^{2-}}$    % Sulfate ion
$^{14}\mathrm{C}$       % Carbon-14 isotope

For better chemistry support, use the mhchem package:

\usepackage{mhchem}
\ce{H2O}                % Simpler syntax
\ce{SO4^{2-}}           % Cleaner appearance

What's the correct syntax for tensor notation subscripts?

Tensor notation typically places superscripts before subscripts for contravariant and covariant indices:

$T^{\mu\nu}_{\rho\sigma}$   % Standard tensor notation
$R^{\alpha}_{\beta\gamma\delta}$    % Riemann curvature tensor
$g_{\mu\nu}$                        % Metric tensor

The tensor package can simplify pre-superscripts and pre-subscripts in tensor notation.

Can I use subscripts in LaTeX text mode (outside of equations)?

Yes! Use \textsubscript{} and \textsuperscript{} commands for text mode subscript notation:

H\textsubscript{2}O is water.
E = mc\textsuperscript{2} is Einstein's equation.

Alternatively, use math mode notation within text:

H$_2$O is water.

How do I avoid deeply nested subscript errors?

Avoid excessive subscript nesting beyond 2-3 levels, as it becomes hard to read:Acceptable nesting:

$x_{i_j}$       % OK: two levels

Problematic nesting:

$x_{i_{j_{k}}}$ % Difficult to read and maintain

Best practice: For complex notation, break expressions into parts for clarity.

What's the best practice for mathematical indices in research papers?

Consistency guidelines for academic subscript notation:

Index naming: Use consistent single letters (i, j, k) throughout
Coordinate systems: Stick to one notation style consistently
Vector notation: Use either subscripts or superscripts consistently
Summation indices: Follow Einstein summation convention in physics
Semantic meaning: Choose meaningful indices: v_x instead of v_1 for x-component

Basic Syntax

Subscripts (Indices)

\documentclass{article}
\usepackage{amsmath}
\begin{document}

% Single character subscript
$x_1$, $x_2$, $x_n$

% Multiple character subscript (requires braces)
$x_{12}$, $x_{n+1}$, $x_{max}$

% Variables with subscripts
$a_i$, $b_j$, $c_{ij}$

% Greek letters with subscripts
$\alpha_1$, $\beta_{n}$, $\gamma_{i,j}$

\end{document}

Rendered Output

Single character:

x_1

x_2

x_n

Multiple characters:

x_{12}

x_{n+1}

x_{max}

Variables:

a_i

b_j

c_{ij}

Greek letters:

\alpha_1

\beta_{n}

\gamma_{i,j}

Superscripts (Exponents)

\documentclass{article}
\usepackage{amsmath}
\begin{document}

% Single character superscript
$x^2$, $x^n$, $x^*$

% Multiple character superscript (requires braces)
$x^{10}$, $x^{2n}$, $x^{n+1}$

% Common exponents
$e^x$, $2^n$, $10^{-3}$

% Special notations
$x^{\prime}$, $x^{\dagger}$, $x^{\ast}$

\end{document}

Rendered Output

Single character:

x^2

x^n

x^*

Multiple characters:

x^{10}

x^{2n}

x^{n+1}

Common exponents:

e^x

2^n

10^{-3}

Special notations:

x^{\prime}

x^{\dagger}

x^{\ast}

Important Rule: Braces for Multiple Characters

Critical: Without braces, only the first character after _ or ^ becomes sub/superscript:

x_12 renders as x₁2 (only 1 is subscript)
x_{12} renders as x₁₂ (both 1 and 2 are subscript)

Combined Subscripts and Superscripts

Basic Combinations

\documentclass{article}
\usepackage{amsmath}
\begin{document}

% Both subscript and superscript
$x_1^2$, $a_n^m$, $x_i^{j+1}$

% Order doesn't matter
$x_1^2 = x^2_1$

% Complex combinations
$x_{n+1}^{2m}$, $a_{ij}^{kl}$

% With operators
$\sum_{i=1}^n$, $\int_0^{\infty}$

% Tensor notation
$T_{\mu\nu}^{\rho\sigma}$

\end{document}

Rendered Output

Both subscript and superscript:

x_1^2

a_n^m

x_i^{j+1}

Order doesn’t matter:

x_1^2 = x^2_1

Complex combinations:

x_{n+1}^{2m}

a_{ij}^{kl}

With operators:

\displaystyle\sum_{i=1}^n

\displaystyle\int_0^{\infty}

Tensor notation:

T_{\mu\nu}^{\rho\sigma}

Nested Subscripts and Superscripts

\documentclass{article}
\usepackage{amsmath}
\begin{document}

% Nested superscripts
$x^{2^n}$, $e^{x^2}$, $2^{2^{2^2}}$

% Nested subscripts
$x_{i_j}$, $a_{n_{k+1}}$

% Mixed nesting
$x_i^{j^k}$, $a_{m_n}^{p^q}$

% Using additional braces for clarity
${(x^2)}^3 = x^6$

% Tower notation
$2^{2^{2^{\cdot^{\cdot^{\cdot}}}}}$

\end{document}

Rendered Output

Nested superscripts:

x^{2^n}

e^{x^2}

2^{2^{2^2}}

Nested subscripts:

x_{i_j}

a_{n_{k+1}}

Mixed nesting:

x_i^{j^k}

a_{m_n}^{p^q}

With braces:

{(x^2)}^3 = x^6

Tower notation:

2^{2^{2^{\cdot^{\cdot^{\cdot}}}}}

Special Use Cases

Limits and Operators

\documentclass{article}
\usepackage{amsmath}
\begin{document}

% Inline limits
$\lim_{x \to 0} f(x)$

% Display style limits
\[\lim_{x \to \infty} \frac{1}{x} = 0\]

% Summation
\[\sum_{i=1}^{n} i = \frac{n(n+1)}{2}\]

% Product
\[\prod_{k=1}^{n} k = n!\]

% Integration
\[\int_0^1 x^2 \, dx = \frac{1}{3}\]

% Multiple limits
\[\lim_{\substack{x \to 0 \\ y \to 0}} f(x,y)\]

\end{document}

Rendered Output

Inline limit:

\lim_{x \to 0} f(x)

Display style limit:

\lim_{x \to \infty} \frac{1}{x} = 0

Summation:

\sum_{i=1}^{n} i = \frac{n(n+1)}{2}

Product:

\prod_{k=1}^{n} k = n!

Integration:

\int_0^1 x^2 \, dx = \frac{1}{3}

Multiple limits:

\lim_{\substack{x \to 0 \\ y \to 0}} f(x,y)

Chemical Formulas

\documentclass{article}
\usepackage{amsmath}
\usepackage{mhchem} % Better chemistry support
\begin{document}

% Basic chemical formulas
$\mathrm{H_2O}$, $\mathrm{CO_2}$, $\mathrm{H_2SO_4}$

% Isotopes
$^{14}\mathrm{C}$, $^{235}\mathrm{U}$, $^2\mathrm{H}$

% Ions
$\mathrm{Na^+}$, $\mathrm{Cl^-}$, $\mathrm{SO_4^{2-}}$

% With mhchem package (recommended)
\ce{H2O}, \ce{CO2}, \ce{H2SO4}
\ce{^{14}C}, \ce{Na+}, \ce{SO4^{2-}}

% Chemical equations
\ce{2H2 + O2 -> 2H2O}

\end{document}

Rendered Output

Basic chemical formulas:

\mathrm{H_2O}

\mathrm{CO_2}

\mathrm{H_2SO_4}

Isotopes:

^{14}\mathrm{C}

^{235}\mathrm{U}

^{2}\mathrm{H}

Ions:

\mathrm{Na^+}

\mathrm{Cl^-}

\mathrm{SO_4^{2-}}

Chemical equation:

2\mathrm{H_2} + \mathrm{O_2} \rightarrow 2\mathrm{H_2O}

Physics and Engineering Notation

\documentclass{article}
\usepackage{amsmath}
\usepackage{tensor} % For tensor notation
\begin{document}

% Vector components
$\vec{v} = v_x\hat{i} + v_y\hat{j} + v_z\hat{k}$

% Derivatives
$\frac{d^2y}{dx^2}$, $\frac{\partial^2 f}{\partial x^2}$

% Tensors
$g_{\mu\nu}$, $R^{\alpha}_{\beta\gamma\delta}$

% Four-vectors
$x^\mu = (ct, x, y, z)$

% Christoffel symbols
$\Gamma^{\lambda}_{\mu\nu}$

% Units
$10^{-9}\,\mathrm{m}$, $3.0 \times 10^8\,\mathrm{m/s}$

\end{document}

Rendered Output

Vector components:

\vec{v} = v_x\hat{i} + v_y\hat{j} + v_z\hat{k}

Derivatives:

\frac{d^2y}{dx^2}

\frac{\partial^2 f}{\partial x^2}

Tensors:

g_{\mu\nu}

R^{\alpha}_{\beta\gamma\delta}

Four-vectors:

x^\mu = (ct, x, y, z)

Christoffel symbols:

\Gamma^{\lambda}_{\mu\nu}

Units:

10^{-9}\,\mathrm{m}

3.0 \times 10^8\,\mathrm{m/s}

Advanced Techniques

Primes and Multiple Primes

\documentclass{article}
\usepackage{amsmath}
\begin{document}

% Single prime
$f'(x)$, $y'$

% Multiple primes
$f''(x)$, $f'''(x)$

% Alternative notation
$f^{\prime}(x)$, $f^{\prime\prime}(x)$

% With subscripts
$x'_1$, $x''_n$

% Prime on subscript
$x_{n'}$, $x_{n''}$

\end{document}

Rendered Output

Single prime:

f'(x)

y'

Multiple primes:

f''(x)

f'''(x)

Alternative notation:

f^{\prime}(x)

f^{\prime\prime}(x)

With subscripts:

x'_1

x''_n

Prime on subscript:

x_{n'}

x_{n''}

Positioning and Spacing

\documentclass{article}
\usepackage{amsmath}
\begin{document}

% Pre-subscripts and superscripts
${}_a^b X_c^d$

% Tensor notation with prescript package
\usepackage{tensor}
\tensor[^a_b]{X}{_c^d}

% Manual spacing adjustments
$x_{\!n}$ % negative thin space
$x_{\,n}$ % thin space
$x_{\:n}$ % medium space
$x_{\;n}$ % thick space

% Phantom subscripts for alignment
\begin{align}
x_1 &= a \\
x_{\phantom{1}2} &= b
\end{align}

\end{document}

Accents with Sub/Superscripts

\documentclass{article}
\usepackage{amsmath}
\begin{document}

% Accents with subscripts
$\hat{x}_i$, $\tilde{y}_n$, $\bar{z}_k$

% Accents with superscripts
$\hat{x}^2$, $\vec{v}^T$, $\dot{x}^n$

% Combined
$\hat{x}_i^2$, $\tilde{\phi}_{nm}^{kl}$

% Wide accents
$\widehat{xyz}_1^2$, $\widetilde{ABC}_{ij}$

\end{document}

Rendered Output

Accents with subscripts:

\hat{x}_i

\tilde{y}_n

\bar{z}_k

Accents with superscripts:

\hat{x}^2

\vec{v}^T

\dot{x}^n

Combined:

\hat{x}_i^2

\tilde{\phi}_{nm}^{kl}

Wide accents:

\widehat{xyz}_1^2

\widetilde{ABC}_{ij}

Text Mode Subscripts and Superscripts

\documentclass{article}
\usepackage{fixltx2e} % For \textsubscript
\begin{document}

% In text mode
H\textsubscript{2}O is water.
E = mc\textsuperscript{2} is Einstein's equation.

% Or use math mode
H$_2$O is water.
E = mc$^2$ is Einstein's equation.

% Ordinals
1\textsuperscript{st}, 2\textsuperscript{nd}, 3\textsuperscript{rd}

% Footnote markers
Text\textsuperscript{a}, Reference\textsuperscript{1}

\end{document}

Rendered Output

In text mode: H

_2

O is water. E = mc

^2

is Einstein’s equation.Ordinals: 1

^{\text{st}}

, 2

^{\text{nd}}

, 3

^{\text{rd}}

Footnote markers: Text

^{\text{a}}

, Reference

^1

Common Errors and Solutions

Error: Double subscript

Problem: x_a_b causes “Double subscript” error.Solution: Use braces to clarify structure:

x_{a_b}    % a with subscript b, all subscript to x
x_a{}_{b}  % separate subscripts a and b

Only first character is sub/superscript

Problem: x_12 shows as x₁2 instead of x₁₂.Solution: Always use braces for multiple characters:

x_{12}     % Correct
x_12       % Wrong

Subscripts in limit are inline

Problem: Limits appear cramped in inline math.Solution: Use display style or \limits:

$\lim\limits_{x \to 0}$     % Forces display style
\[\lim_{x \to 0}\]          % Use display math

Prime notation conflicts

Problem: x'^2 doesn’t work as expected.Solution: Use proper grouping:

{x'}^2     % Correct
x'^2       % May cause issues
x^{\prime 2}  % Alternative

Best Practices

1. Readability Guidelines

Good Practices:

Use meaningful subscripts: v_x not v_1 for x-component
Avoid deep nesting: x_{i_j} is okay, deeper is confusing
Be consistent: If using i,j,k for indices, stick to it
Use semantic notation: \max not max

Poor Practices to Avoid:

Overusing sub/superscripts: x_{a_{b_{c_{d}}}}
Mixing notation styles in same document
Using subscripts for non-mathematical text
Forgetting braces: x_min instead of x_{min}

2. Consistency Rules

Indices: Use consistent letters (i, j, k or m, n, p)
Coordinates: Be consistent (x, y, z or r, θ, φ)
Time derivatives: Choose notation and stick to it (ẋ or dx/dt)
Vector components: Consistent notation (subscripts or superscripts)

3. Special Notation Standards

% Tensors - superscripts before subscripts
$T^{\mu\nu}_{\rho\sigma}$  % Correct
$T_{\rho\sigma}^{\mu\nu}$  % Less standard

% Derivatives - use consistent notation
$\frac{\partial^2 f}{\partial x^2}$  % Standard
$f_{xx}$                              % Alternative

% Units - use upright text
$10^{-3}\,\mathrm{m}$     % Correct
$10^{-3}\,m$              % Wrong (italic m)

4. Accessibility Considerations

Avoid excessive nesting that’s hard to read
Use \text{} for words in subscripts: x_{\text{max}}
Consider alternative notations for complex expressions
Break very complex expressions into parts

Quick Reference Card

Command	Result	Description
`x_1`	$x_1$	Single subscript
`x^2`	$x^2$	Single superscript
`x_{12}`	$x_{12}$	Multiple character subscript
`x^{2n}`	$x^{2n}$	Multiple character superscript
`x_i^j`	$x_i^j$	Combined sub/superscript
`\sum_{i=1}^n`	$\displaystyle\sum_{i=1}^n$	Summation limits
`\lim_{x \to 0}`	$\displaystyle\lim_{x \to 0}$	Limit notation
`f'(x)`	$f'(x)$	Prime notation
`{}_{a}^{b}X_{c}^{d}`	${}_a^b X_c^d$	Pre-superscript/subscript
`\textsubscript{2}`	H $_2$ O	Text mode subscript
`^{14}\mathrm{C}`	$^{14}\mathrm{C}$	Isotope notation
`T^{\mu\nu}_{\rho}`	$T^{\mu\nu}_{\rho}$	Tensor notation

Mathematical Expressions

Basic math mode and LaTeX subscript expressions

Equations Guide

Multi-line and numbered equations

Matrices & Arrays

Matrix notation with subscript indices

LaTeX Symbols Reference

Complete symbol reference for subscripts

Chemistry Notation

Chemical formula subscript notation

Physics Notation

Physics symbols and tensor notation

Getting Started

LaTeX Basics

Text & Formatting

Mathematics

Figures & Tables

Specialized Notation

Bibliography & References

Advanced Topics

​What You’ll Learn

​Frequently Asked Questions

​Basic Syntax

​Subscripts (Indices)

Rendered Output

​Superscripts (Exponents)

Rendered Output

​Important Rule: Braces for Multiple Characters

​Combined Subscripts and Superscripts

​Basic Combinations

Rendered Output

​Nested Subscripts and Superscripts

Rendered Output

​Special Use Cases

​Limits and Operators

Rendered Output

​Chemical Formulas

Rendered Output

​Physics and Engineering Notation

Rendered Output

​Advanced Techniques

​Primes and Multiple Primes

Rendered Output

​Positioning and Spacing

​Accents with Sub/Superscripts

Rendered Output

​Text Mode Subscripts and Superscripts

Rendered Output

​Common Errors and Solutions

​Best Practices

​1. Readability Guidelines

​2. Consistency Rules

​3. Special Notation Standards

​4. Accessibility Considerations

​Quick Reference Card

​Related Topics

Mathematical Expressions

Equations Guide

Matrices & Arrays

LaTeX Symbols Reference

Chemistry Notation

Physics Notation

​Further Reading & References

What You’ll Learn

Frequently Asked Questions

Basic Syntax

Subscripts (Indices)

Superscripts (Exponents)

Important Rule: Braces for Multiple Characters

Combined Subscripts and Superscripts

Basic Combinations

Nested Subscripts and Superscripts

Special Use Cases

Limits and Operators

Chemical Formulas

Physics and Engineering Notation

Advanced Techniques

Primes and Multiple Primes

Positioning and Spacing

Accents with Sub/Superscripts

Text Mode Subscripts and Superscripts

Common Errors and Solutions

Best Practices

1. Readability Guidelines

2. Consistency Rules

3. Special Notation Standards

4. Accessibility Considerations

Quick Reference Card

Related Topics

Further Reading & References