10-20 layers, Large Fowl how big of a run do they need?

[CrazyFowlFreak]

Thank you all for the advice

I will probably keep it at 10-15 max for birds. We have a fenced in area that they will free range in daily, even in winter, that is 40X150ft. So I guess I need to get a good idea of how big to make the run for if we need to lock them all inside a run for some reason. Sorry I wasn't more clear in my original post.