I’m 22 and while my facial hair grows nicely in some areas, overall it is very patchy. So how old were you before you could grow a full beard, assuming of course you can. Oh well at least I’m not going bald. 
I remember having to start shaving regularly around age sixteen or seventeen. Regularly back then meaning, about once every two weeks.
As time went on, though, the need to shave became more frequent unless I WANTED a full-grown beard (which I didn’t and still don’t). To avoid that, I have to shave about every three or four days (and it’s been like that since I was about nineteen or twenty).
I’m 30 and I still can’t.
About 22-23. I grew one just to see if I could. It didn’t last long before I shaved it off again. I’ve been clean shaven ever since.
22; I can grow the “abe,” but I’ve only begun to sprout little mustache hairs! Dammit, hurry up facial hair!
When I went on my Mormon mission at 20, I only shaved everyday to fit in with the crowd.
I’d say I was in my mid- to late-twenties before I could grow a beard. Hell, I was using single blade disposable razors until my 30s.
I’m 41 and though I can sprout a presentable goatee I still can’t grow a decent full beard. This is probably related to the fact that I also have no chest hair. (Upside: no back hair!)
I was about 18 before my moustache was properly presentable. Other than that, I thin kI had a full beard by the time I was 16.
On the other hand, I don’t think I can blame my receding hairline on a ‘widow’s peak’ any more.
Mid 20s in my case. I’m now 35 and just shaved off a full beard. It will stay shaved 
Ditto.
I’m 25 and I still can’t. There’s a Y-shaped section under my lips that doesn’t grow hair much. The “arms” of the Y are on either side of the soul patch area, and the stem of the Y runs down the fron of my neck. Lately, the bare part on the front of my neck has been filling in; in a few months I may only have a V-shaped section of non-beard.
It’s hard to say because I used to shave. But in my early twenties I grew a full beard and moustache* and have kept them ever since.
I did shave it all off for charity (it took 90 minutes!), then grew it all back in 3 weeks.
*I’m 3rd from the left at the back…
I’m 45 and I’m still waiting for it to grow in everywhere…
17 for the beard, 19 for the mustache. The beard “mutton-chopped” it’s way in.
I had a 'stache at 20, but I was 44 before I had a full beard.
I am 26 and it has only been in the past few months that I would have been able to grow a proper beard - and I just got engaged a few months ago, any correlation? From about 21 until now I could grow a weak beard; though I could have grown a full neck beard from the time I was 19.
Actually, I have just realized that I need to shave daily to maintain a “fresh” look. I can go two days but I’ll have the rustic look the second day. If I let it go past that I get the shaggy (nasty) look. And since my fellow grad students are about 80% female - and the fact I’m engaged - I keep away from the shag as much as possible.
17 or 18
I have a very heavy beard, thick head o’ hair, and a very hairy chest (but no back hair - go figure).
About 20ish. I’m 38 so I’ve had to shave daily for the last 18 years. Fun.
Me too. I was growing wicked sideburns in high school but the mustache didn’t really fill in until about 20-21. At 25, it’s still filling in.
I didn’t really have to shave until I was 20 or so, and even now, it just grows sparse and raggedy and looks like shit everywhere except my chin. It’s that part-Asian thing. 