On Aug 20, 10:42 am, khalid wrote:
How do I calculate the z factor automatically by using
Hall-Yarborogh equation without changing (Y) every time
to reach F=0 ?

This relates to a high-specialized area of engineering. If you
posted
the formulas here, __maybe__ someone could help you. But I suspect
this requires more knowledge of the science than of Excel. You might
get some "hint" by looking at z.xls that apparently comes with the
book "Petroleum Production Engineering" by Boyun Guo (2007).

PS: Please do not "crosspost" manually in multiple related groups.