Here is some general info:
IF your birds will be in the coop for almost 24/7 then you NEED 10 sq feet per bird for a Standard (Large Fowl) bird. And generally 8 sq. feet for a bantam. Which means for your silkies, you could have a 4x6, 2x12, or 3x8 coop. This is only if they will be inside.
Now, if you have a run for them, then you will need 4 sq. feet for a large bird, and about 3 sq. feet for your birds INSIDE the coop. If you do have a run, the run is 10 sq. ft. per bird for a large bird, but about 6 sq. ft for a bantam.
If you want three silkies per coop I am assuming you have a run? So then you would need a 3x3 coop to have 9 sq. ft. And you would have either a 2x9 run or a 3x6 run.
Does this help?
Also, a little math:
Area = Length x Width
(measured in Square feet.)
i have the coop already. this is just the run. for the 3 silkies i was planning to do a 6 foot by 3 foot pen. which would be 18 sqft, 6 sqft per bird. i am also going to let them free range at least 2 hours a day, when i am home. does this sound good? thanks for your answer!
Yep sounds fine to me.