Contents
Defining CSS font sizes
The CSS font-size
property allows you to set the default font size in HTML documents or elements:
The default value is medium
, which equals to 16 pixels. Descendants of the element with a CSS font size defined will inherit it unless they have their font size defined individually.
Writing font-size: CSS syntax
To set a CSS font size, follow the syntax example below:
font-size: value;
All the available property values will be defined in the following section.
Theory is great, but we recommend digging deeper!
Property values
Value | Definition |
---|---|
Keywords | Define the CSS font size as xx-small , x-small , small , medium , large , x-large or xx-large
|
Numeric values | Define the CSS font size in absolute values (e.g., pixels or millimeters) |
Percentages | Define the CSS font size in relation to the font size of the parent container in percentages |
Relative values | Define the CSS font size as larger or smaller in relation to the font size of the parent container |
Browser support

Chrome
1+

Edge
12+

Firefox
1+

IE
5.5+

Opera
7+

Safari
1+
Mobile browser support

Chrome
18+

Firefox
4+

Opera
10.1+

Safari
1+