# fancyhdr not centering after changed geometry

I have a document with different page margins, so I have to change geometry settings after fancyhdr loaded. However, the width of header after geometry is not correct.

\documentclass[12pt]{article}
\usepackage[left=35mm, right=35mm]{geometry}
\usepackage{fancyhdr}
\pagestyle{fancy}

\begin{document}
It's fine here.
\newpage

\newgeometry{left=25mm, right=25mm}
PROBLEM: The line of header is 20mm narrower than expected here.
\end{document}


How can I solve this problem?

• You have to set the \geometry first, then \fancyhead. So in this instance, you have to reset the header. Have you tried that? Ideally, make a complete, minimal working example (MWE) that one can copy-and-paste to reproduce your problem. – Werner Dec 25 '12 at 5:04
• @Werner Thanks for your advices, and I've added the MWE. Also, how to "reset" the header? – Haocheng Dec 25 '12 at 5:39

Here's a MWE

\documentclass{article}
\usepackage[margin=1in]{geometry}
\usepackage{fancyhdr}
%% \fancy@setoffs changed name to \f@nch@setoff at some point.
%% Checking whether \f@nch@setoff exists - if not we define it to be the old \fancy@setoffs:
\makeatletter
\ifcsname f@nch@setoffs\endcsname\else%
%% If \fancy@setoffs does not exis, then we assume old version define it to be
%% fancy@setoffs, which is the old name for it:
\let\f@nch@setoffs\fancy@setoffs
\fi
\makeatother
\pagestyle{fancy}
\makeatletter
\makeatother

\usepackage{lipsum}
\begin{document}

\lipsum[1-3]

\pagebreak
\newgeometry{margin=1.5in}

\lipsum[1-3]

\pagebreak
\newgeometry{margin=0.75in}

The key here is the new command \resetHeadWidth which calls the fancyhdr macro for defining the header and footer widths.
• Cool, I also had this issue, and this solution worked out fine for me. (I wonder if fancyhdr maintainers shouldn't mention this in the package documentation.) – pedrosanta Nov 21 '16 at 13:13
• Worth noting: in the lastest version of the fancyhdr package, the macro \fancy@setoffs has been renamed to \f@nch@setoffs. – Erlend Graff Jul 30 '17 at 15:17