How many nesting boxes?

[HenHouse10C]

Currently we have a 4x6 raised pitch-roofed coop with an attached 4x14 run, and plenty of space to free range outside of that. We have 3 eight week old black sex link pullets in it right now, and 3 more that will be joining them in about a month. Then after that, we are going to have 3 more lavender orpingtons join in once they're feathered out (we get the chicks tomorrow, so excited!) I understand what comes with integrating the flocks.. What I want to know is how many nesting boxes are necessary for 9-10 girls? There's 4 built in to the coop as it is now but they can easily be removed and the space turned into roosting space. Thoughts?

 

[chickens r life]

Chickens are happy to wait their turn for the nesting boxes. I think people normally say 1 nesting box every three birds (don't quote me on that I'm not totally sure). But 4 is plenty.