On average for INSIDE coopage it is recommended to have at LEAST minimum 4 sq ft per standard chicken. So for that size, it would be 30 Sq ft inside, divided by 4=7 chickens maximum.
However, in my experience...its better to go with at least 5 sq ft per bird, so that would give you 6 chickens in that space.
Outside room is good to have tho... its recommended 10 sq ft per standard sized chicken. So, with a 6 x 8 run added on (for example), that is 48 sq feet, or 4-5 chickens.
If they have access to outdoors then 7 (4 sq. ft. per bird) hens. If they don't then only 3 (10 sq ft/bird). The more room outdoors the less likely they get bored and feather pick.
i have a 5x6x9 coop and 4x2 hall way out to a 12 x10 pen with a top on it .all my chickens are fine i have 11 in it .
working on a day pen 20x 20 it will not have a top on it. jest a day pen do i need to put a top on it?
I'm new to the chicken thing
It somewhat depends on your climate too. If the chickens have to stay cooped during extreme winter weather, you want as much space as possible per bird= 5 s/f. each at least. If you don't have cold winter weather and they can spend all year outside during the day, you can have a lot less space and still not have problems. My coop is a 3 sided 4'x8' open air design. The 'rule' would be only 8 chickens in there, but I have 13 right now and have had more than that. But mine only sleep in there, and not all of them. Some roost outside on perches and 3 roost up on top of my carport frame that is inside their run (which is 12'x25'). My nestboxes are outside the coop in a sheltered area so they don't even go in the coop to lay. They aren't crowded, just really have no need of shelter since we have really mild winters here.