40 - 19 inch relay racks covering 3 sides of a room, 2 - 6 foot tall function table racks on wheels, an IBM card reader, and an IBM summary card punch. you figure the math out.
ENIAC weighed 30 tons and covered up to 1800 sq. feet. It took massive amounts of energy so it had to be cooled down once in a while (not sure what once in a while is) and had to be repaired...