CSS supports a number of measurements including absolute units such as inches, centimeters, points, and so on, as well as relative measures such as percentages and em units. Table B-2 summarizes these units of measure.
|
Measurement |
Description |
Example |
|---|---|---|
|
% |
Defines a measurement as a percentage relative to another value, typically an enclosing element. |
p {font-size: 14pt; line-height: 150%;} |
|
cm |
Defines a measurement in centimeters. |
div {margin-bottom: 1cm;} |
|
em |
A relative measurement for the height of a font in em spaces. Because an em unit is equivalent to the size of a given font, if you assign a font to 12pt, each 'em' unit would be 12pt; thus, 2em would be 24pt. |
p {letter-spacing: 5em;} |
|
ex |
This value defines a measurement relative to a font's x-height. The x-height is determined by the height of the font's lowercase letter x. |
p {font-size: 14pt; line-height: 2ex;} |
|
in |
Defines a measurement in inches. |
p {word-spacing: .25in;} |
|
mm |
Defines a measurement in millimeters. |
p {word-spacing: 12mm;} |
|
pc |
Defines a measurement in picas. A pica is equivalent to 12 points; thus, there are 6 picas per inch. |
p {font-size: 10pc;} |
|
pt |
Defines a measurement in points. A point is defined as 1/72nd of an inch. |
body {font-size: 14pt;} |
|
px |
Defines a measurement in screen pixels. |
p {padding: 15px;} |