LaTeX/Useful Measurement Macros

A list of macros and their values

Units

First, we introduce the LaTeX measurement units. All LaTeX units are two-letter abbreviations. You can choose from a variety of units. Here are the most common ones.

Abbreviation	Definition	Value in points (pt)
pt	a point is 1/72.27 inch, that means about 0.0138 inch or 0.3515 mm.	1
mm	a millimeter	2.84
cm	a centimeter	28.4
in	inch	72.27
ex	roughly the height of an 'x' in the current font	undefined, depends on the font used
em	roughly the width of an 'M' (uppercase) in the current font	undefined, depends on the font used

And here are some less common units.

Abbreviation	Definition	Value in points (pt)
bp	a big point is 1/72 inch, that means about 0.0139 inch or 0.3527 mm.	1.00375
pc	pica	12
dd	didôt (1157 didôt = 1238 points)	1.07
cc	cîcero (12 didôt)	12.84
sp	scaled point (65536sp per point)	0.000015

Length 'macros'

Some length commands are;

\baselineskip 

The normal vertical distance between lines in a paragraph

\baselinestretch 

Multiplies \baselineskip

\columnsep 

The distance between columns

\columnwidth 

The width of the column

\evensidemargin 

The margin for 'even' pages (think of a printed booklet)

\linewidth 

The width of a line in the local environment

\oddsidemargin 

The margin for 'odd' pages (think of a printed booklet)

\paperwidth 

The width of the page

\paperheight 

The height of the page

\parindent 

The normal paragraph indentation

\parskip 

The extra vertical space between paragraphs

\tabcolsep 

The default separation between columns in a tabular environment

\textheight 

The height of text on the page

\textwidth 

The width of the text on the page

\topmargin 

The size of the top margin

\unitlength 

Units of length in Picture Environment

Length manipulation macros

You can change the values of the variables defining the page layout with two commands. With this one you can set a new value:

\setlength{parameter}{length}

with this other one, you can add a value to the existing one:

\addtolength{parameter}{length}

You can create your own length with the command:

\newlength{parameter}

You may also set a length from the size of a text with one of these commands:

\settowidth{parameter}{some text}
\settoheight{parameter}{some text}
\settodepth{parameter}{some text}

When using these commands, you may duplicate the text that you want to use as reference if you plan to also display it. But LaTeX also provides a set of commands to avoid this duplication:

\newsavebox{boxname}
\savebox{boxname}{some text}
\usebox{boxname}

You may wish to look at the example below to see how you can use these. The command \newsavebox creates a placeholder for storing a text; the command \savebox stores the specified text in this placeholder, and does not display anything in the document; and \usebox recalls the content of the placeholder into the document.

See LaTeX/Page_Layout for samples using these.

Samples

Resize an image to take exactly half the text width :

\includegraphics[width=0.5\textwidth]{mygraphic}

Make distance between items larger (inside an itemize environment) :

\addtolength{\itemsep}{0.5\baselineskip}

Use of savebox to resize an image to the height of the text:

% Create the holders we will need for our work
\newlength{\mytitleheight}
\newsavebox{\mytitletext}
% Create the reference text for measures
\savebox{\mytitletext}{%
  \Large\bfseries This is our title%
}
\settoheight{\mytitleheight}{\usebox{\mytitletext}}
% Now creates the actual object in our document
\framebox[\textwidth][l]{%
  \includegraphics[height=\mytitleheight]{my_image}%
  \hspace{2mm}%
  \usebox{\mytitletext}%
}