What is the optimal size for nesting boxes?

[swampman]

I am just about finished building a coop for my 16 girls. The coop is 6'x8', up on stilts about 2' off the ground. I am ready to build the nesting boxes and would wondering what the best size would be. I am using 1"X12" rough cut lumber for the construction of the nesting boxes. Is 12"x12"x12" ok, or should it be wider and taller?

 

[CoyoteMagic]

Depends on your birds. My BSL like a bigger box. I'm using a large covered litterbox now that everybody uses.

 

[RocketDad]

I have a 5' long box, divided into 5 nests, for 5 hens. About 1' deep, 1' tall, but with a slope at the back from the roof/egg door.

They all use the same nest, but which one varies from from day to day. I've seen my three largest hens in one at the same time, with another hen on the roost trying to get in.

 

[BankerJohn]

I use a plastic Coca-Cola crate originally designed to hold a case of soda.