Unit of length that can be used in CSS
| Unit | Unit Name | Explanation |
|---|---|---|
| Absolute length units | ||
| mm | millimeter | 10mm = 1cm |
| cm | centimeter | 1cm = 10mm |
| in | inch | 1in = 2.54cm |
| pt | point | 72pt = 1in |
| pc | pica | 1pc = 12pt |
| Relative length units | ||
| em | em | 1em = the current height of the font |
| ex | x-height | 1ex = the current height of the "x" character |
| px | pixels | 1px = one dot on the screen |
| Percentage unit | ||
| % | percentage | - |
In CSS, some unit must be specified for length values. However, only when a value is zero, the unit can be omitted.
About "em"
1em is the current font size (It is based on "M" character). If the current font size is 14pt, 1em becomes 14pt.
- 1em = 14pt
- 2em = 28pt
- 0.5em = 7pt