Troy Ounce

The traditional unit of weight for gold is the troy ounce, named, it is thought, after a weight used at the annual fair at Troyes in France in the Middle Ages. Although the metric system is used increasingly in mining and the gold business, the troy ounce remains the basic unit in which the price of 995 gold is quoted. One troy ounce = 31.1034807 grams, 32.15 troy ounces = 1 kilogram, 1 troy ounce = 480 grains, 1 troy ounce = 20 pennyweights (North American jewellery trade), 3.75 troy ounces = 10 tolas (Indian sub-continent), 6.02 troy ounces = 5 taels (Hong Kong), 1 troy ounce = 155.52 metric carats (diamonds/precious stones).