Defining page margins with \geometry for two-sided documents

Question

How do you set page margins using \geometry for a two-sided document? So far I've used the twoside option in my documentclass, which automatically widens the left/right margin on opposite sides of odd and even pages.

Edit: My inquiry is not strictly practical, as I wish to know how to achieve the same results 'without' the twoside option.

Answer 1

Normally, one would simply use the left and right keys, because they are actually synonyms for inner and outer in twoside mode. (Alternatively, one could specify the textwidth and hmarginratio keys.) In case you want to disable the swapping of margins on alternate pages, add the asymmetric option.

\documentclass[twoside]{article}

\usepackage[top=2cm,bottom=4cm,left=1.5cm,right=3cm,asymmetric]{geometry}

\usepackage{lipsum}

\begin{document}

\lipsum[1-15]

\end{document}

EDIT: So far you've used the twoside option in your document class, but you want to do without this option? Well, use the twoside option of geometry instead.