Cooking: Food Volume

Different ways to cut: Dice, Mince, Slice, and Julienne

Onion

Food to other metrics (approximations):
Small onion = 4 ounces by weight or about ½ cup chopped
Medium onion = 8 ounces, or about 1 cup chopped
Large onion = 12 ounces, or about 1½ cups chopped
Jumbo onion = 16 ounces, or about 2 cups chopped

From my experience:
1 pint container = 3 small onions (Julienne, loosely packed), 4 small onions (Julienne)

Medium Shells (Pasta Noodles)

1 lb medium shells (cooked) = 3 quarts (loosely packed)

Reference:
http://spinarecipe.com/cooking.php?cook=31
http://cooking.stackexchange.com/questions/13479/how-much-is-a-small-medium-large-onion