booktabs

name	booktabs
description	LaTeX booktabs/tabularx/multirow/longtable packages for professional tables. Use when helping users create well-formatted tables, multi-page tables, or improve table appearance.

booktabs + tabularx + multirow + longtable — Professional Tables

CTAN: https://ctan.org/pkg/booktabs | https://ctan.org/pkg/tabularx
Manual: texdoc booktabs

Setup

\usepackage{booktabs}    % professional horizontal rules
\usepackage{tabularx}    % auto-width columns
\usepackage{multirow}    % cells spanning rows
\usepackage{longtable}   % multi-page tables
\usepackage{colortbl}    % colored rows/cells (optional)
\usepackage{siunitx}     % number alignment (optional)

Ugly vs Professional — Before/After

❌ Bad Table

\begin{tabular}{|l|c|r|}
\hline
Name & Score & Grade \\ \hline
Alice & 95 & A \\ \hline
Bob & 82 & B \\ \hline
Carol & 78 & C \\ \hline
\end{tabular}

✅ Good Table

\begin{tabular}{lcc}
\toprule
Name  & Score & Grade \\
\midrule
Alice & 95    & A \\
Bob   & 82    & B \\
Carol & 78    & C \\
\bottomrule
\end{tabular}

Rules: Never use vertical lines. Never use \hline. Use \toprule, \midrule, \bottomrule.

booktabs Rules

Command	Use
\toprule	Top of table (thicker)
\midrule	Between header and body
\bottomrule	Bottom of table (thicker)
\cmidrule(lr){2-4}	Partial rule spanning columns 2–4
\addlinespace	Extra vertical space (group separator)
\addlinespace[5pt]	Custom extra space

cmidrule Trimming

\cmidrule(l){1-2}   % trim left
\cmidrule(r){3-4}   % trim right
\cmidrule(lr){2-3}  % trim both
\cmidrule{1-4}      % no trim

Grouped Rows Example

\begin{tabular}{llr}
\toprule
Category & Item   & Price \\
\midrule
Fruit    & Apple  & 1.20 \\
         & Banana & 0.80 \\
\addlinespace
Dairy    & Milk   & 2.50 \\
         & Cheese & 4.00 \\
\bottomrule
\end{tabular}

tabularx — Auto-Width Columns

% X columns expand to fill \textwidth
\begin{tabularx}{\textwidth}{lXr}
\toprule
ID & Description & Price \\
\midrule
1  & A very long description that will wrap automatically & \$10 \\
2  & Short & \$20 \\
\bottomrule
\end{tabularx}

Column type	Behavior
l, c, r	Fixed (natural width)
X	Expands to fill remaining space (left-aligned)
>{\centering\arraybackslash}X	Centered X column
>{\raggedleft\arraybackslash}X	Right-aligned X column
p{3cm}	Paragraph, fixed width

multirow

\usepackage{multirow}

\begin{tabular}{lcr}
\toprule
\multirow{2}{*}{Name} & \multicolumn{2}{c}{Scores} \\
\cmidrule(l){2-3}
 & Math & English \\
\midrule
Alice & 95 & 88 \\
Bob   & 72 & 91 \\
\bottomrule
\end{tabular}

Syntax: \multirow{nrows}{width}{content} — use * for auto width.

\multicolumn{ncols}{alignment}{content} — built into LaTeX.

Complex Header Example

\begin{tabular}{lcccccc}
\toprule
& \multicolumn{3}{c}{Treatment A} & \multicolumn{3}{c}{Treatment B} \\
\cmidrule(lr){2-4} \cmidrule(lr){5-7}
Subject & Pre & Post & $\Delta$ & Pre & Post & $\Delta$ \\
\midrule
1 & 5.2 & 3.1 & $-2.1$ & 4.8 & 4.5 & $-0.3$ \\
2 & 6.1 & 2.8 & $-3.3$ & 5.5 & 5.2 & $-0.3$ \\
\bottomrule
\end{tabular}

longtable — Multi-Page Tables

\usepackage{longtable}

\begin{longtable}{lcc}
% Header for first page
\toprule
Name & Value & Unit \\
\midrule
\endfirsthead

% Header for continuation pages
\multicolumn{3}{l}{\textit{Continued from previous page}} \\
\toprule
Name & Value & Unit \\
\midrule
\endhead

% Footer for all pages except last
\midrule
\multicolumn{3}{r}{\textit{Continued on next page}} \\
\endfoot

% Footer for last page
\bottomrule
\endlastfoot

% Data rows
Alpha   & 1.0 & m \\
Beta    & 2.5 & kg \\
% ... many more rows ...
Omega   & 9.9 & s \\

\caption{Long experimental data.}
\label{tab:longdata}
\end{longtable}

Note: longtable replaces tabular entirely (not inside table environment). Caption and label go inside.

colortbl — Row and Cell Coloring

\usepackage{colortbl}
\usepackage[table]{xcolor}  % or load xcolor with table option

% Colored row
\rowcolor{blue!10}
Alice & 95 & A \\

% Colored cell
Alice & \cellcolor{green!20} 95 & A \\

% Alternating row colors (xcolor table option)
\rowcolors{2}{gray!10}{white}  % start at row 2, alternate
\begin{tabular}{lcc}
\toprule
\rowcolor{white}  % override for header
Name & Score & Grade \\
\midrule
Alice & 95 & A \\  % gray
Bob & 82 & B \\    % white
Carol & 78 & C \\  % gray
\bottomrule
\end{tabular}

siunitx S Columns — Number Alignment

\usepackage{siunitx}

\begin{tabular}{l S[table-format=3.2] S[table-format=1.3]}
\toprule
{Material} & {Density} & {Error} \\
\midrule
Steel      & 785.00    & 0.050 \\
Aluminum   & 270.00    & 0.120 \\
Titanium   & 450.00    & 0.008 \\
Gold       & 1932.00   & 0.300 \\
\bottomrule
\end{tabular}

S column: Aligns numbers by decimal point. Wrap text headers in {...}.

S option	Example	Meaning
table-format	3.2	3 digits . 2 decimals
table-format	+2.1e3	sign, digits, exponent
round-mode	places	Round to decimal places
round-precision	2	Number of decimal places

Full Example — Publication-Quality Table

\begin{table}[htbp]
  \centering
  \caption{Performance comparison of algorithms.}
  \label{tab:comparison}
  \begin{tabular}{l S[table-format=2.1] S[table-format=3.0] c}
    \toprule
    {Method} & {Accuracy (\%)} & {Time (ms)} & {Converged?} \\
    \midrule
    Baseline   & 72.3 & 150 & Yes \\
    Improved   & 85.1 & 230 & Yes \\
    Proposed   & 91.7 &  98 & Yes \\
    \addlinespace
    Oracle     & 99.2 &  45 & N/A \\
    \bottomrule
  \end{tabular}
\end{table}

Common Pitfalls

Problem	Cause	Fix
Vertical lines	Using `	` in column spec
\hline	Old habit	Use \toprule/\midrule/\bottomrule
Table too wide	Too many columns	Use tabularx with X columns, or \resizebox
longtable in table	Incompatible	longtable replaces table environment
\multirow misaligned	Row height differences	Add \rule{0pt}{2.5ex} or adjust manually
S column header error	Text in S column	Wrap header in {...}
Footnotes in table	\footnote fails in tabular	Use \tablefootnote (tablefootnote pkg) or threeparttable
booktabs + colortbl gaps	Rules have gaps with color	Add \abovetopsep=0pt or use \arrayrulecolor

Tips

• Three rules only: \toprule, \midrule, \bottomrule — almost never need more
• Use \addlinespace to group rows visually instead of extra rules
• Put \caption above the table (convention for tables, unlike figures)
• \small or \footnotesize before tabular to shrink wide tables
• threeparttable package for proper table footnotes
• \arraystretch to adjust row height: \renewcommand{\arraystretch}{1.2}