Measurements

Question

Hi, Please what is the full meaning of the pc , em and ex in terms of measurements and how are their conversions. And among these three, which one will you prefer?

Answer 1

1pc = 12pt
1pt = 1/72 of an inch

2em = 2 times the current font size, relative to font size
ex is relative to x-height of font

Basically these are used all in different moments, em for instance is great for text because it can be scaled very easilly and has great support.

Though generally there 2 types of measurements: absolute and relative

Absolute are: cm, pt, px, pc, etc.
They are based on actual sizes (px for instance is not actual pixels but 1/96 of an inch)

Relative are: em, ex, rem, %, etc.
These are based on relative sizes that can change and are used for perfectly scalable layouts.

I would recommend only using px for absolute sizes and search more on the relative ones to understand where to use each, but there is no better one, just the right one for the situation.