# Centre column head with siunitx

Consider this example

\documentclass{report}
\usepackage{siunitx}
\begin{document}
\begin{tabular}{l S}
A & {sf}\\
0 & 9887779.1\\
0 & 9999.1 \\
\end{tabular}
\end{document}


In the output

the column head is centred on the decimal point. How to centre the column head in the middle of the column?

Adding the vertical lines can tell you why this happens (don't add vertical lines in your actual document!). The following screenshots are taken in the same scale to the actual PDF file.

It is using [table-format=7.7]. You have to change it to [table-format=7.2]:

\documentclass{report}
\usepackage{siunitx}
\begin{document}
\begin{tabular}{l S[table-format=7.2]}
A & {sf}\\
0 & 9887779.11\\
0 & 9999.1 \\
\end{tabular}
\end{document}


With vertical lines added to highlight the "centerity":