Here's some sample text, with various font-size property values applied. Change the default font size in your browser and see what effect it has on the different values.
This line appears in the default font-size provided by your browser right now.
This line appears with a font-size: 85% specified.
This line appears with a font-size: 120% specified.
This line appears with a font-size: xx-small specified.
This line appears with a font-size: x-small specified.
This line appears with a font-size: small specified.
This line appears with a font-size: smaller specified.
This line appears with a font-size: medium specified.
This line appears with a font-size: larger specified.
This line appears with a font-size: large specified.
This line appears with a font-size: x-large specified.
This line appears with a font-size: xx-large specified.
This line appears with a font-size: .2in specified.
This line appears with a font-size: 5mm specified.
This line appears with a font-size: .5cm specified.
This line appears with a font-size: 12pt specified.
This line appears with a font-size: 1pc specified.
This line appears with a font-size: 1.2em specified.
This line appears with a font-size: 2.4ex specified.
This line appears with a font-size: 12px specified.
Once again, this line appears in the default font-size provided by your browser right now.
If you have the Verdana font installed, this paragraph appears in that font. You may notice that Verdana is larger than the Arial or browser-assigned sans-serif font used on the rest of this page.
The following are the default sizes for headers on your browser right now (note that headers are also often boldfaced):
Last revised 7 Nov 2009