Ems

The em is a relative font measurement. Why does it have a funny name, “EM”? What’s that?

The “em” represents the size of the capital letter M.

In CSS, 1em is equal to the user’s default font size. This is usually the browsers default, 16px.

1em = 16px

1em may also represent the font size of the parent element. Which is why it is loosely described as the “current font size”.

Since I’m not certain you understood that, let’s see examples.

A simple declaration with fonts looks like this: