How many kilos of rice to feed 400 people?

One pound of rice makes ten 3/4 cup servings (1/4 cup dry, 3/4 cup cooked). So, for 400 people, you would need 40 pounds of rice for 400 people, if the serving size is the average 3/4 cup portion. If you want to allow 1 cup per serving, you would need to increase the amount of dry rice by 25%, which would be 50 pounds of rice.