Wooden boxes?

[Ilovemychicks08]

Around August 11th ill be showing my chickens at a fair for the first time. I already know to wash them and trim nails/beaks. But carriers.
Ive seen wooden ones for bantams, which i am going to make one for the single bantam im taking. But for LF like a Orpington or Brahma what size box is best?
Does anyone have plans they made?

 

[RossAcres]

Honestly I just eyeball it most of the time. You want it to be big enough that they aren't squished, because that will ruin their feathers. But you don't want it big enough that they can turn and move around freely.

 

[Ilovemychicks08]

Honestly I just eyeball it most of the time. You want it to be big enough that they aren't squished, because that will ruin their feathers. But you don't want it big enough that they can turn and move around freely.

Thanks!
So making it for each chicken specifically.
The bantams will be easy as they are their full size along with most of my LF. Except my cochins.