how many grams in an ounce of gold

An ounce of gold contains approximately 31.1035 grams. This is based on the troy ounce, which is the standard unit of measurement used specifically for precious metals like gold and silver. The troy ounce differs from the common avoirdupois ounce (used for everyday items), which weighs about 28.35 grams. For gold and other precious metals, the troy ounce is used worldwide for trading and pricing, and it equals exactly 31.1034768 grams