A quarter cow should feed one person for a year
The average adult meat-eater can eat a 1/2-3/4lb serving of meat in a sitting, 2-3 times a week. Remember you may have some friends and family to entertain throughout the year, also.
A quarter beef will equal approximately 110 pounds of meat, and depending on your processing choices, 5%-50% of that will be ground beef, and the other part will be primal cuts (steaks, roasts, brisket, ribs, etc.).