The run is definitely the limiting factor here.
If the coop is wide open to the run, like mine, you can get by with a few more birds in the space. I've got a 8 X 10 coop and a 10 X 10 covered run for a total of 180 sq ft, average flock size is about 20, give or take a few cockerels/grow outs. But keep in mind, this is an established flock with a stable pecking order. I need that outer pen when integrating chicks or new adult birds.
View attachment 1235377
The outer pen is under construction while I repair the fencing that bears have trampled.
Rule of thumb, minimum 4 sq ft per chicken in coop & 10 sq ft per in the run. However BIGGER the better, more space less issues with the flock. And the worst is Chicken Math