Plan a dinner party menu.
A seated dinner party uses smaller portions than a buffet because guests are served rather than helping themselves, and because there are multiple courses. Six ounces of protein per guest is right for a four-course meal; eight to ten would apply if the main were the whole meal. Each side dish is portioned separately at around five ounces a head, so three sides means fifteen ounces of side per guest in total — which is why adding a fourth side increases shopping more than people expect. The prep estimate is deliberately included: roughly 45 minutes per course of cooking plus about nine minutes per guest of plating, serving and clearing, which is the constraint that actually limits a dinner party.
Dinner Party Menu
Protein lb = guests x protein oz / 16; sides lb = guests x side oz x number of sides / 16; prep hours = courses x 0.75 + guests x 0.15
Six ounces for a multi-course seated meal, eight to ten if the main course stands alone. Buy raw weight above this to allow for trimming and cooking loss.
Three or four for a home dinner party. Beyond that the prep time rises faster than the guests' appetite, and the host spends the evening in the kitchen.