How much prime rib for 30 people?

For a gathering of 30 people, you should plan on serving about 1 pound of prime rib per person if it's the main dish, which totals around 30 pounds. However, if you're serving multiple courses or sides, you can reduce that to about 0.5 to 0.75 pounds per person, resulting in approximately 15 to 22.5 pounds. It's always good to round up slightly to ensure there is enough for everyone.