Troy Ounce
Also: Troy Ounce, oz t, Ounce, ozt
The globally standard unit of weight in precious metals trading: one troy ounce equals exactly 31.1034768 grams of pure precious metal.
The troy ounce (abbreviated oz t or ozt) is the internationally valid unit of measurement in which gold, silver, platinum and palladium are traded. One troy ounce equals exactly 31.1034768 grams. Important: the troy ounce always refers to the amount of pure precious metal, not to the gross weight of a piece of jewellery or a coin.
The troy ounce is not the same as the avoirdupois ounce
In everyday life we encounter the trade ounce (avoirdupois ounce) of about 28.35 grams - for example with foodstuffs. The troy ounce used in the precious metals market is heavier and goes back to the medieval weight system of the French city of Troyes. Anyone comparing prices should therefore look closely: a "price per ounce" in the gold trade practically always means the troy ounce of 31.1035 grams.
Why the troy ounce is so important for the price
The current gold price and the silver price are quoted on the world markets in US dollars per troy ounce. To get from there to the value of a specific bar or a coin, one converts to grams:
- 1 troy ounce = 31.1034768 g
- 1 gram = 0.0321507 troy ounces
- 1 kilogram = 32.1507 troy ounces
A classic 100-gram gold bar therefore contains around 3.215 troy ounces of fine gold. You can most quickly determine the exact equivalent in euros with the gold calculator or - for any units - with the unit converter.
The troy ounce in investment coins
Many well-known investment coins such as the Krugerrand, the Maple Leaf or the Vienna Philharmonic contain exactly one troy ounce of fine gold. With coins made of a copper alloy (such as the Krugerrand) the total weight is higher than 31.1 grams, however, because the added alloying metal comes on top - but the fine gold content remains exactly one ounce. Besides the full ounce, fractional sizes are also common: 1/2 oz, 1/4 oz, 1/10 oz and sometimes 1/20 oz.
In brief
The troy ounce is the pivot of every price quotation in the precious metals market. Anyone who knows it can effortlessly convert world market prices, bar weights and coin denominations into one another - and immediately recognises whether an offer is fairly calculated.