How much rigatoni for 15 people?

For a group of 15 people, you typically need about 1 to 1.5 ounces of dry rigatoni per person as a main dish. This translates to approximately 15 to 22.5 ounces, or about 1 to 1.5 pounds of dry rigatoni. It's always a good idea to round up a bit to ensure everyone is satisfied, so preparing around 1.5 to 2 pounds would be a safe estimate.