4' octagon coop can fit 19 chickens, does this sound right?

[ncCHICKS]

I am making plans for building a chicken gazebo. I am wanting to make it in the shape of an octagon and have each side 4'. My, and a few others math shows 19 chickens! Does this seem right?

 

[TillinWithMyPeeps]

Yes, that would be a little over 4 square feet per bird which should be fine.