Standard size chickens need 4 sq. ft. per bird indoors and 10 sq. ft. outdoors. So 53x4=212 sq. ft of indoor space and 53x10=530 sq. ft. outdoors. Broilers may do alright with a bit less space but don't crowd too much. Bantams can be slightly less as well at about 3sq. ft./bird indoors and 8 sq. ft./ bird outside.
2 sq ft per bird indoors is the absolute minimum under good conditions. 4 or more makes for more comfort and less potential problems if they have to stay indoors for awhile for weather. Last thing you need is cannibalism in the coop in the winter.