Are all fonts will take same space on browser with same value?

Are all fonts size would be same with same value?

for example p { font-family:Arial; font-size:12px}

if i change Arial to any other font th开发者_StackOverflowen will all fonts will render in same size as Arial render in 12px, in all browser?

Short answer: No.

I'm not entirely sure of the historical reason for this, though here's one example of the convoluted history that you're dealing with if you want to understand typography in detail.

As empirical proof of this answer, try pasting this code into a text file and opening the file in a browser:

<div style="font-family:Arial; font-size:12px">This is 12 point type.</div><br />
<div style="font-family:Times New Roman; font-size:12px">This is 12 point type.</div><br />

Well, it will most likely render differently on Windows vs. OS X, even if it is the same font.