You are here: Reference > appendix > css > length
Length
The syntax for lengths is a number immediately followed by a unit identifier.
You can use lengths for the value of several style properties (width, height, left, top, right, bottom, font-size, etc.).
Some properties allow negative length values, but if a negative length value is set on a property that does not support it, the declaration is dropped.
There are two types of length units:
| 1. | - | Relative length units specify lengths relative to other measures. Pages using relative length units can be scaled more easily from one device to another. | |
| 2. | - | Absolute length units define absolute measurements which are useful if the physical properties of the output device are known. |
Units
| Unit | Description |
|---|---|
| Relative length units | |
| em | The font-size of the relevant element. |
| ex | The x-height of the relevant element's font. This is commonly the height of the lowercase 'x'. |
| px | Pixels, relative to the viewing device. The px unit identifies a simple pixel, although for printers and very high resolution screens it may identify multiple pixels. |
| Absolute length units | |
| in | inches (1 inch is equal to 2.54cm) |
| cm | centimeters |
| mm | millimeters |
| pt | points (1 point is equal to 1/72 inches) |
| pc | picas (1 pica is equal to 12 point) |
External links:
User Contributed Comments