About 2 cups of dry macaroni make 4 cups cooked. Pasta usually doubles in size when it is cooked. When left sitting in hot sauce or soup, pasta's volume increases even more.
Cook 2 cups of macaroni in at least 2 quarts of water to avoid a sticky, mushy result. Use cold tap water or bottled or filtered water if the tap water has a disagreeable taste. Bring the water to a boil over high heat.
Add the macaroni and ½ tablespoon of salt to the boiling water. Stir the macaroni frequently to keep it from sticking. Boil the macaroni for the time recommended on the package. Most types take between eight and 12 minutes. It is finished when it is tender but firm.
Drain the macaroni into a colander. Shake and stir it to encourage the water to drain out.
Slightly undercooked pasta can be added to simmering sauce or soup to finish cooking. Avoiding putting the macaroni into soup too early, because it absorbs broth as it cooks.
Four cups of cooked pasta provide eight nutritional servings of ½ cup each. For practical purposes, use 1 cup per person for a side dish and 2 cups per person for a main course.