What is the difference between toprule, midrule and bottomrule?

They are the three horizontal rules booktabs provides: toprule above the header, midrule between the header and the body, and bottomrule at the end. They are thicker or thinner than a plain hline and add vertical padding, which is why journal tables look cleaner with them.

How do I remove the vertical lines from a LaTeX table?

Leave them out of the column specification: write {lcr} rather than {|l|c|r|}. Professional typesetting convention is no vertical rules at all, and booktabs is designed around that.

How do I merge cells in a LaTeX table?

Use \multicolumn{n}{c}{text} to span n columns, and \multirow{n}{*}{text} from the multirow package to span n rows. A multicolumn also lets you override the alignment for that one cell.

How do I make a table fit the page width in LaTeX?

Use tabularx with a total width and an X column, which absorbs the remaining space, or wrap the tabular in \resizebox from graphicx. tabularx is preferable because it keeps the font size consistent with the body text.

Why is my LaTeX table not where I put it?

A tabular inside a table float is placed by LaTeX where it fits, and [h] is only a hint. To force the position, use [H] from the float package, or leave the tabular outside a float entirely.

How to format tables in LaTeX

Build a table in LaTeX with the tabular environment: declare a column spec (l left, c centre, r right), separate cells with &, and end each row with \\. For publication-quality rules, load booktabs and use \toprule, \midrule, and \bottomrule instead of \hline.

\begin{tabular}{l c r}
  Method   & Acc.  & Time \\
  Baseline & 0.81  & 12s  \\
  Ours     & 0.94  & 3s   \\
\end{tabular}

A three-column LaTeX table with left, centred and right aligned columns, no rules.

A complete document you can paste

\documentclass{article}
\usepackage{booktabs}

\begin{document}

\begin{table}[t]
  \centering
  \begin{tabular}{lcr}
    \toprule
    Method   & Accuracy & Time \\
    \midrule
    Baseline & 0.81     & 12s  \\
    Ours     & 0.94     & 3s   \\
    \bottomrule
  \end{tabular}
  \caption{Accuracy and runtime.}
  \label{tab:results}
\end{table}

As Table~\ref{tab:results} shows, the method is faster and more accurate.

\end{document}

A booktabs table with toprule, midrule and bottomrule, a caption reading 'Accuracy and runtime', and a sentence referring to it as Table 1.

Clean, publication-quality rules

Avoid vertical lines and double rules. booktabs gives you \toprule, \midrule, and \bottomrule — the convention almost every journal expects — with the right thickness and spacing built in.

Spanning cells

\multicolumn spans columns and can override the alignment for that cell; multirow adds \multirow for spanning rows.

\usepackage{booktabs}
\usepackage{multirow}
% ...
\begin{tabular}{lcc}
  \toprule
  & \multicolumn{2}{c}{Scores} \\
  \cmidrule(lr){2-3}
  Method & Dev & Test \\
  \midrule
  \multirow{2}{*}{Ours} & 0.92 & 0.94 \\
                        & 0.91 & 0.93 \\
  \bottomrule
\end{tabular}

A booktabs table where a multicolumn header spans two score columns above a cmidrule, and a multirow cell spans two rows.

Tables that fit the page

tabularx takes a target width and an X column that absorbs whatever is left, so a wide table wraps instead of running into the margin.

\usepackage{tabularx}
% ...
\begin{tabularx}{\linewidth}{lX}
  Term & Description that can be long and will wrap neatly \\
\end{tabularx}

A two-column tabularx table filling the text width, with a long description wrapping inside the X column.

Floating tables & captions

Wrap the tabular in a table float to add a caption and make it referenceable: \caption{…} then \label{tab:results}, cited with \ref{tab:results}.

Writing in Typst instead? Tables in Typst covers the equivalent, and the style gallery has copy-paste variants.

In KL studiothe preview recompiles as you tweak column specs, so you see the alignment change immediately instead of waiting on a full rebuild — handy when a wide table keeps overflowing the margin.

Common questions

What is the difference between toprule, midrule and bottomrule?: They are the three horizontal rules booktabs provides: toprule above the header, midrule between the header and the body, and bottomrule at the end. They are thicker or thinner than a plain hline and add vertical padding, which is why journal tables look cleaner with them.
How do I remove the vertical lines from a LaTeX table?: Leave them out of the column specification: write {lcr} rather than {|l|c|r|}. Professional typesetting convention is no vertical rules at all, and booktabs is designed around that.
How do I merge cells in a LaTeX table?: Use \multicolumn{n}{c}{text} to span n columns, and \multirow{n}{*}{text} from the multirow package to span n rows. A multicolumn also lets you override the alignment for that one cell.
How do I make a table fit the page width in LaTeX?: Use tabularx with a total width and an X column, which absorbs the remaining space, or wrap the tabular in \resizebox from graphicx. tabularx is preferable because it keeps the font size consistent with the body text.
Why is my LaTeX table not where I put it?: A tabular inside a table float is placed by LaTeX where it fits, and [h] is only a hint. To force the position, use [H] from the float package, or leave the tabular outside a float entirely.