Six Keys to Select a Chicken Breed... Number 2

This is a article from the magazine Backyard Poultry By: Brandon Mitchell from Tennessee.

                                        2  SIZE MATTERS
Size is another factor, and probably the most important one to consider if your birds will be confined to a small area. Chickens range from the tiny 20 ounce Dutch bantam to the monstrous 13 pound Black Jersey Giant and everywhere in between. (Both the Dutch bantam and the Jersey Giant breeds were feathered in the December 2011 / January 2012 issue of Backyard Poultry. - Ed.) 
                         Most catalogs break down chicken breeds into bantams and standard chickens, but you should consider their individual breed weight when filling a coop. The Dutch, Sebright, and Old English Game bantam are the smallest at 18-24 ounces. Bantam Ameraucanas, Wyandottes, Cochins, and Polish are a little larger (26-32 ounces), and Brahmas, Plymouth Rocks, and Rhode Island Reds are the largest ranging from 34-40 ounces. That's a big size difference when you consider a Dutch bantam chick is only about half the size of a bantam Barred Rock chick. The smallest standard chickens (at about four or five pounds) are the Leghorns, Hamburgs, Ameraucanas, Polish and Anconas. Rhode Island Reds, New Hampshire, Black Australorps, Wyandottes, Naked Necks, Delawares, Sex-Links, and Andalusians range from 5.5 - 6.5 ponds. The Plymouth Rocks, Orpingtons, Sussex, Cochins, and Minorcas range from 7 -9 pounds, and Brahmas and Giant are jumbos, tipping the scales at more than nine pounds from hens. One Brahama weight about as much as six Sebrights, four bantam Wyandottes, or two Hamburgs. In a limited space, smaller is better, but on the open range, larger chickens are somewhat less susceptible to predation , although you'll still lose some.