Chapter 1

Sizing text using em units.

The em is a sliding measure. One em is a distance equal to the type size. In 6 point type, an em is 6 points; in 12 point type an em is 12 points and in 60 point type an em is 60 points. Thus a one em space is proportionately the same in any size.

IE/Win will not allow readers to resize text that has been sized in pixels. Using ems however, allows all browsers to resize text and also provides pixel-level precision and so they tend to be my unit of choice.

Using Ems

Here are the Ems -> Pixels:

• 1em = 10px
• 1.2em = 12px
• .9em = 9px
• 1.8em = 18px
• 2em = 24px

Source:
Book: Bulletproof Web Design
http://clagnut.com/blog/348