How to calculate the physical print dimensions of a string?

I have to print a string in a cell with autoheight and specific width , and I want to know how many lines it will take in the printed A4 page in pdf (I will convert the write document to pdf). Is there any BASIC macro to calculate that?

Or at least is there any BASIC macro to calculate the width of a single printed string (specific string, specific font, printing will be in pdf, so I think screen will be good enough for reference)?