Lee Smith 07 December 2005 1em != 1pt. That was the whole point of this article. em is a relative (sliding) measurement. That’s really the main advantage to using em fonts sizes instead of pt or px. When you use em, the font sizes are rendered relative to the user’s browser font size. Like in IE, the em is relative to the View -> Text sizes (Medium by default I think) and you can increase and decrease as you please. But for all those people that set their font sizes in fixed pt or px in their css, they essentially take this functionality away from the users.