calculation the font size and line height

Hello, I hope to post in the right section.

I am reading a few articles about typography and besides being very interesting is however quite complex.

In this case I want to know if I understand correctly.

The font size and line height depends to the content width. right?

**Case 1**

For the case that i have a blog with two columns. The first content is 160px and the other is 700px. The font size and the line height must be different for these two contents or must be the same?

font-size:1em (16px). *I use 1em*

font : Drop Sans

I found a useful tool to calculate to find the font size and the line height , but i am a little confused.

http://www.pearsonified.com/typography/

How i find the Golden Ratio, also how to calculate and find the best solution of font-size and line height?

Thanks in advance.