I just returned from my daily grocery hunt. I made a point of checking out the weight of chickens. They ranged from 1.2 to just under 1.5 kg. That is, I believe, 2lb 10oz to 3lb 5oz.
The only chickens larger than that were what @Katie Meadowrefers to above, but even these came nowhere near 5lb - just over 4lb. They are old layers which no one would ever use for white cut chicken. It would be inedible. They are sold for making stocks and broth, although most are used industrially to make chicken bouillon and fertilizer.