How many grains are in an ounce?

An ounce includes approximately 437.5 grains. The grain can be calculated in terms of an imperial unit of weight, and is part of the outdated system of units that have been used in the United States. One grain is equal to approximately 0.06479891 grams. So, an ounce, which corresponds to approximately 28.35 grams, can also be calculated with the approximate range of 437.5 grains.