How many pounds of beef roast for 70 people?

To serve 70 people, you generally need about 0.5 pounds of cooked beef per person, which translates to approximately 35 pounds of cooked beef roast. However, beef roasts typically lose about 25% of their weight during cooking. Therefore, you should plan on starting with around 46-50 pounds of raw beef roast to ensure everyone is adequately served.