what does an ounce equal to
a unit of weight equal to one sixteenth of a pound (avoirdupois); 1 ounce is equal to 437.5 grains or 28.349 grams oz. 2. a unit of weight equal to one twelfth of a Troy or Apothecaries' pound; 1 ounce is equal to 480 grains or 31.103 grams.