2008 Oct 17
| Name | Abrev | Note |
|---|---|---|
| Centimeters | cm | |
| Inches | in | |
| Millimeters | mm | |
| Pica | pc | |
| Pixels | px | 72/inch .. 96/inch .. 120/inch |
| Points | pt | 72/inch |
Most length units can be a positive or negative number followed by a label, although some properties do not accept negative numbers. Decimal fraction numbers are allowed, e.g. 3.14.
CSS2 recommends 90px/in, while CSS2.1 recommends 96px/in. CSS1 made the mistake of using screen pixels as printer pixels, which could be 600/in.
| Abrev | Note |
|---|---|
| em | Value of font-size, e.g. if font-size is 12 pixels then 1em is 12 pixels. |
| ex | Height of a lower case x in current font. Some have 1ex=0.5em |
| px | May not allow user to resize text! |