About 10 pounds of spaghetti or any kind of pasta are needed to feed 80 people. However, this estimate is based on the average serving per person and could be low or high depending on individual appetites.
Barilla brand pasta recommends 2 ounces of pasta per person. That number is multiplied by the number of people, which is 80, equalling 160 ounces. One pound has 16 ounces, so the number of ounces, 160, is divided by the number of ounces in a pound, 16. One-hundred and sixty divided by 16 is equal to 10, meaning 10 pounds of spaghetti are needed for that amount of people.