FontSize

Larger than the parent element's font size, by roughly the ratio used to separate the absolute size keywords above.

Smaller than the parent element's font size, by roughly the ratio used to separate the absolute size keywords above.

Wrap the provided expression in CSS calc() function.

ch represents the width, or more precisely the advance measure, of the glyph "0" (zero, the Unicode character U+0030) in the element's font.

em represents the calculated font-size of the element. If used on the font-size property itself, it represents the inherited font-size of the element.

1 pt is 4/3 of a pixel.

Pixels

rem represents the font-size of the root element (typically ). When used within the root element font-size, it represents its initial value (a common browser default is 16px, but user-defined preferences may modify this).

1 vh is equal to 1% of the height of the viewport's initial containing block

1 vmax is equal to the larger of 1 vw and 1 vh

1 vmin is equal to the smaller of 1 vw and 1 vh

1 vw is equal to 1% of the width of the viewport's initial containing block