unc.edu: ounce Citat: "...a traditional unit of weight. The avoirdupois ounce, the unit commonly used in the United States, is 1/16 pound or about 28.3495 grams...a second traditional unit of mass or weight. The troy ounce, traditionally used in pharmacy and jewelry, is 1/12 troy pound, 480 grains, or about 31.1035 grams..."
unc.edu: fluid ounce Citat: "...In the U. S. customary system there are 16 fluid ounces in a pint, so each fluid ounce represents 1.804 687 cubic inches or 29.573 531 milliliters. In the British Imperial system there are 20 fluid ounces in an Imperial pint, so each fluid ounce represents about 1.733 871 cubic inches or 28.413 063 milliliters..."
