LaTeX Last column is too large compared to other multicolumns

Question

\begin{table}[H]
\centering
\begin{tabular}{c c c c c c c}
\hline
\multirow{2}{*}{\textbf{Metal}} & \multicolumn{3}{c}{\textbf{Initial temperature, $\pm 0.01 (\ang{-}C)$}} & \multicolumn{3}{c}{\textbf{Final temperature, $\pm 0.01 (\ang{-}C)$}} \\ \cline{2-7} 
                       &  \textbf{1} & \textbf{2} & \textbf{3} & \textbf{1} & \textbf{2} & \textbf{3}   \\ \hline
Iron                   & $18.1$  & $19.0$  & $18.7$  & $21.9$  & $24.3$  & $24.4$  \\ 
Zinc                   & $18.9$  & $18.9$  & $18.8$  & $32.7$  & $38.5$  & $41.0$  \\ 
Magnesium              & $18.8$  & $18.7$  & $18.9$  & $72.8$  & $76.4$  & $75.8$  \\
Tin                    & $19.0$  & $18.9$  & $18.6$  & $20.1$  & $20.9$  & $19.4$  \\ 
Aluminium              & $18.7$  & $18.9$  & $18.7$  & $18.8$  & $18.9$  & $18.7$  \\ \hline
\end{tabular}
\caption{Initial and final temperatures of metals reacting with Copper Sulphate solution}
\end{table}

The last column of this is too large because the Initial temp and final headers are too large. How can I make all of the multicolumn widths the same?

@Bernard if I were to guess it's siunitx' command to write angles. — cgnieder, Jan 07 '21 at 20:02
@cgnieder: Maybe, but what does it have to do with temperatures? — Bernard, Jan 07 '21 at 20:08

score 4 · Answer 1 · answered Jan 07 '21 at 20:20

Please always provide a complete test file, I had to guess \ang and the text width here. However you can force the columns to be wide enough to take the spanning entry using w from array

\documentclass[a4paper]{article}
\usepackage{float,multirow,array}
\newcommand\ang[1]{??}
\addtolength\textwidth{50pt}
\begin{document}
\begin{table}[H]
\centering
\setlength\extrarowheight{2pt}
\begin{tabular}{@{}l {6}{wc{45pt}}@{}}
\hline
\multirow{2}{}{\textbf{Metal}} & \multicolumn{3}{c}{\textbf{Initial temperature, $\pm 0.01 (\ang{-}C)$}} & \multicolumn{3}{c}{\textbf{Final temperature, $\pm 0.01 (\ang{-}C)$}} \ \cline{2-7} 
                       &  \textbf{1} & \textbf{2} & \textbf{3} & \textbf{1} & \textbf{2} & \textbf{3}   \ \hline
Iron                   & $18.1$  & $19.0$  & $18.7$  & $21.9$  & $24.3$  & $24.4$  \ 
Zinc                   & $18.9$  & $18.9$  & $18.8$  & $32.7$  & $38.5$  & $41.0$  \ 
Magnesium              & $18.8$  & $18.7$  & $18.9$  & $72.8$  & $76.4$  & $75.8$  \
Tin                    & $19.0$  & $18.9$  & $18.6$  & $20.1$  & $20.9$  & $19.4$  \ 
Aluminium              & $18.7$  & $18.9$  & $18.7$  & $18.8$  & $18.9$  & $18.7$  \ \hline
\end{tabular}
\caption{Initial and final temperatures of metals reacting with Copper Sulphate solution}
\end{table}
\end{document}

score 4 · Answer 2 · answered Jan 07 '21 at 20:29

Here is a different approach based on siunitx, booktabs and another \multicolumn that contains all the repeated information. With this approach, there is no need to articifially stretch the columns:

\documentclass{article}
\usepackage{siunitx}
\usepackage{makecell}
\usepackage{booktabs}
\begin{document}
\begin{table}
\centering
\begin{tabular}{l *{6}{S[table-format=1.2]}}
\toprule
\textbf{Metal} & \multicolumn{6}{c}{\bfseries Temperature, \SI{\pm 0.01}{\celsius}}\
\cmidrule{2-7}
               & \multicolumn{3}{c}{\bfseries Initial} &  \multicolumn{3}{c}{\bfseries Final} \ 
\cmidrule(r){2-4} \cmidrule(l){5-7}
               &  \textbf{1} & \textbf{2} & \textbf{3} & \textbf{1} & \textbf{2} & \textbf{3}   \
                       \midrule
Iron                   & 18.1  & 19.0  & 18.7  & 21.9  & 24.3  & 24.4  \ 
Zinc                   & 18.9  & 18.9  & 18.8  & 32.7  & 38.5  & 41.0  \ 
Magnesium              & 18.8  & 18.7  & 18.9  & 72.8  & 76.4  & 75.8  \
Tin                    & 19.0  & 18.9  & 18.6  & 20.1  & 20.9  & 19.4  \ 
Aluminium              & 18.7  & 18.9  & 18.7  & 18.8  & 18.9  & 18.7  \ 
\bottomrule
\end{tabular}
\caption{Initial and final temperatures of metals reacting with Copper Sulphate solution}
\end{table}
\end{document}

score 1 · Answer 3 · answered Jan 07 '21 at 20:50

I would provide more structure in the table's header -- and not overload any single piece of information.

\documentclass{article}
\usepackage{siunitx} % for '\SI' macro
\usepackage{booktabs}
\begin{document}
\begin{table}
\centering
\begin{tabular}{ @{} l cccccc @{}}
\toprule
& \multicolumn{6}{c}{Temperatures, in \si{\celsius}} \\
\cmidrule(l){2-7}
& \multicolumn{3}{c}{Initial} & \multicolumn{3}{c}{Final} \\ 
\cmidrule(lr){2-4} \cmidrule(l){5-7}
Metal & 1 & 2 & 3 & 1 & 2 & 3 \\
\midrule
Iron      & 18.1  & 19.0  & 18.7  & 21.9  & 24.3  & 24.4  \\ 
Zinc      & 18.9  & 18.9  & 18.8  & 32.7  & 38.5  & 41.0  \\ 
Magnesium & 18.8  & 18.7  & 18.9  & 72.8  & 76.4  & 75.8  \\
Tin       & 19.0  & 18.9  & 18.6  & 20.1  & 20.9  & 19.4  \\ 
Aluminium & 18.7  & 18.9  & 18.7  & 18.8  & 18.9  & 18.7  \\
\bottomrule
\multicolumn{7}{@{}l}{\footnotesize Note: All temperatures are accurate to${}\pm\SI{0.1}{\celsius}$.}
\end{tabular}
\caption{Initial and final temperatures of metals reacting with copper sulphate solution}
\end{table}
\end{document}

Bernard · Answer 4 · 2021-01-07T20:58:00.693

I propose to use siunitx for the alignment of the numerical columns, and to fix the width of the S columns so that the multicolumns contents is not too wide for the sum of the widths of these S columns.

In addition, I propose various improvements: using the rules from booktabs, which adds some vertical padding around horizontal rules, splitting the \multicolumns onto two lines with makecell packages, etc.

\documentclass[]{article}
\usepackage{multirow, makecell, booktabs}
\usepackage{float}
\usepackage{siunitx}
\renewcommand{\theadfont}{\normalsize\bfseries}
\begin{document}
\begin{table}[H]
\centering\sisetup{detect-weight, table-format=2.1, table-number-alignment=center, table-column-width=8mm}
\begin{tabular}{c*{7}{S}}
\toprule
\multirow{3.5}{*}{\textbf{Metal}} &amp; \multicolumn{3}{c}{\thead{Initial temperature\\\SI[detect-weight]{\pm 0.01}{\celsius}}} &amp; \multicolumn{3}{c}{\thead{Final temperature, \\ \SI{\pm 0.01}{\celsius}}} \\  \cmidrule(lr){2-4}\cmidrule(lr){5-7}
                       &amp; {\bfseries 1} &amp; {\bfseries 2} &amp; {\bfseries 3} &amp; {\bfseries 1} &amp; {\bfseries 2} &amp; {\bfseries 3} \\ \midrule
Iron &amp; 18.1 &amp; 19.0 &amp; 18.7 &amp; 21.9 &amp; 24.3 &amp; 24.4 \\
Zinc &amp; 18.9 &amp; 18.9 &amp; 18.8 &amp; 32.7 &amp; 38.5 &amp; 41.0 \\
Magnesium &amp; 18.8 &amp; 18.7 &amp; 18.9 &amp; 72.8 &amp; 76.4 &amp; 75.8 \\
Tin &amp; 19.0 &amp; 18.9 &amp; 18.6 &amp; 20.1 &amp; 20.9 &amp; 19.4 \\
Aluminium &amp; 18.7 &amp; 18.9 &amp; 18.7 &amp; 18.8 &amp; 18.9 &amp; 18.7 \\ \bottomrule
\end{tabular}
\caption{Initial and final temperatures of metals reacting with Copper Sulphate solution}
\end{table}


\end{document}

LaTeX Last column is too large compared to other multicolumns

4 Answers4