Units in LaTeX

Discrete units

These are your basic units, like inches, centimeters, and points. Conversion of units from here and here.

These tables show the relative sizes of each unit:

Relative sizes of units in LaTeX, inches

Relative sizes of units in LaTeX, cm

Units defined relative to font sizes

There also are sizes that are relative to the current font face and font size. The size ex is usually the same as the height of an "x", and the size em is usually (but less often) equal to the width of an "M".

Since these are relative to your font, don't be surprised if your attempts look different than mine. Just like their absolute sizes, the size of ex relative to em is not consistent across fonts.

Examples of font-relative units

Units defined relative to document There also are units that have definitions relative to your document. These are determined based on your documentclass, and can also be explicitly changed.

A list of these and how to change them is available here. Some of the sizes are illustrated here.

command size
\paperwidth Width of page
\paperheight Height of page
\textwidth Width of text
\textheight Height of text
\linewidth Width of a line, usually equal to \textwidth, but varies with environment
\columnwidth Width of a column, usually same as \linewidth
\columnsep Distance between columns
\tabcolsep Separation between columns in a tabular environment
\parindent Paragraph indentation
\parskip The extra vertical space between paragraphs
\baselineskip Vertical distance between lines in a paragraph
\baselinestretch Multiplies \baselineskip
\unitlength Units of length in a picture environment
\topmargin Size of top margin
\evensidemargin Margin of even pages
\oddsidemargin Margin of odd pages

Next, we'll learn how to use these units to add white space.