Part of the equation of “how long to grow a beard” involves the color of your facial hair. If it is dark it will take less time to look presentable than if it is lighter in color. Also, both the thickness of the individual hairs and the thickness of hairs per sq area of skin will each have an effect. I’m not convinced that facial hair grows at enormously different rates between different men…there are too many variables, and no hard data that I’ve seen.
Having said all of that, it takes me about two weeks to look OK. The suggestion to shape the beard area by shaving rather early does help to define the fact that you are growing a beard…it will look much better.
Sunstone…bearded guy for the last 35 years.