A dozen eggs a week per two or three people is a common target.
Good layers (Leghorns, Australorps) run high; heritage or older birds, lower.
It starts from the eggs you want each week and divides by how many a hen of your chosen productivity lays, then applies standard space rules of thumb — about 4 sq ft of coop and 10 sq ft of run per hen — plus a typical feed rate of roughly 1.5 lbs per hen per week. Round up: a couple of spare hens cover molting and short winter days.
Where you keep chickens matters too. Local ordinances on flock size and roosters vary widely, so confirm the rules for your county before you build. To find chicken-friendly states, see our best states for raising chickens guide.
Plan on roughly one hen per two eggs you want each day. A productive hen lays about 5 eggs a week, so a family wanting two dozen eggs a week needs about 5 hens. Add one or two extra to cover molting, slow winters, and the occasional non-layer.
A common rule of thumb is about 4 square feet of coop and 8–10 square feet of outdoor run per standard hen. Crowding causes pecking, disease, and fewer eggs, so err on the generous side, especially if the birds are confined in winter.
A standard laying hen eats roughly a quarter-pound of feed per day, or about 1.5 pounds a week. Scraps and foraging offset some of that, but laying hens need a complete layer ration with enough protein and calcium to keep producing.