One troy ounce is 31.1035 grams
The troy ounce is an old English unit used only for precious metals. It is heavier than the ordinary ounce (28.35 g): 1 troy ounce = 31.1034768 grams.
From price per troy ounce to price per gram
Divide by 31.1035. At €3,593 per troy ounce, gold costs €115.52 per gram of fine gold.
Formula. price per gram = price per troy ounce ÷ 31.1035
And back. price per troy ounce = price per gram × 31.1035
And back. price per troy ounce = price per gram × 31.1035
From grams to kilos
A kilo is 1,000 grams, or 32.15 troy ounces. Silver bars are often traded per kilo: silver now costs €1,548 per kilo.
Don't forget fineness
Prices are for fine metal. For jewellery, multiply by the fineness: 14 ct is 0.585, sterling silver 0.925. More in fineness and hallmarks.