Border thickness
border-width
Set the thickness of an element's border.
Property values
This property is used to set each of these four border width properties, which may also be set one by one:
- border-top-width
- border-right-width
- border-bottom-width
- border-left-width
This property expects anywhere from one to four values, with their interpretation as follows:
number of values | sides effected |
---|---|
1 value | Sets all four sides: top, right, bottom, left |
2 values | 1st value: top and bottom edges 2nd value: right and left edges |
3 values | 1st value: top edge 2nd value: right and left edges 3rd value: bottom edge |
4 values | 1st value: top edge 2nd value: right edge 3rd value: bottom edge 4th value: left edge |
Use any of these font-relative typographic units to set the width:
em | em | The font-size of the current font |
rem | relative em | The font-size of the <html> element |
lh | line height | The line-height of the current font |
rlh | relative line height | The line-height of the <html> element |
cap | cap height | The nominal height of the current font's capital letters |
ex | "x" | The height of the current font's "x" glyph |
ch | "0" | The advance measure (the width) of the current font's "0" glyph |
ic | ideograph count | The advance measure (the width) of the current font's "水" ideograph |
Or use any of these fixed size units which are independent of the current font:
in | inch | A size equal 96px |
px | pixels | A size equal to 1/96 inch |
pt | point | A size equal 1in/72 = 1.33px |
pc | pica | A size equal 1in/6 = 12pt = 16px |
cm | centimeter | A size equal to 96px/2.54 = 37.8px |
mm | millimeter | A size equal to 96px/25.4 = 3.8px |
Q | quarter millimeter | A size equal to 96px/1016 = 0.94px |