What is the em font-size unit? How much is it in pixels?

Question

I want to know what the em unit is, and how much 1em is when converted to pixels (px). I also read somewhere about some IE bug, to overcome which b

Answer 1

this link can help you http://jontangerine.com/log/2007/09/the-incredible-em-and-elastic-layouts-with-css

As quoted from that article:

We know that 1em is always equal to the font size of the parent element, therefore:

1 ÷ parent font-size × required pixel value = em value

For your bookmarks: Pixel to ems conversion table for font sizes.