There are different ounces

Ounce of Gold or Troy Ounce of Gold - What's the Difference?

  • Troy ounce: 31.1034768 grams
  • Standard weight measurement for pure precious metal
  • Basis of precious metal price quotations on the stock exchange
  • Also an important standard in the coin trade
  • Ounce: Generic term for various weights

What exactly does troy ounce mean?

1 troy ounce = 31.1034768 grams

The troy ounce (English: troy ounce, abbreviated is now the internationally standardized standard measure of weight for precious metals. Precious metal prices are quoted in this unit of weight and in dollars. In addition, the troy ounce as a unit is popular in trade. Especially when it comes to investment coins, the troy ounce is considered the classic par excellence.

The ounce (abbreviation: oz) is a general generic term for an old, non-metric measure of weight, which can be understood to mean different weights depending on the era or culture. So there is no such thing as "the" ounce.

This weight measure originally comes from antiquity. For the Romans this was 27.2875 grams. As a result, the ounce was used in many regions and for various purposes, sometimes with different weights, for example for weighing grain, as a pharmacist's ounce, or as a liquid ounce for perfumes.

In English-speaking countries, the "common ounce" (= "avoirdupois ounce") is still occasionally used as a unit of weight for food. It is 28.35 grams.

Ounce and Troy Ounce: What's the Difference?

Even if, strictly speaking, it should be "troy ounce" for precious metals, the colloquial abbreviation "ounce" is also often used in the precious metal trade. What is meant is always the unit of weight 31.1034768 grams.

The 1 ounce Krugerrand has been the most popular gold coin for years. Like many other investment coins, this coin is also available as 1/2 ounce, 1/4 ounce, 1/10 ounce or 1/20 ounce:

Denominations of one troy ounce of gold in comparison: Krugerrand (1/10, 1/4, 1/2, 1 oz) and Maple Leaf additionally with 1/20 oz.

For precious metal bars, metric weight classes are more common, i.e. information in grams or kilos. Ounce units are also available. There are other bar weight classes in fractions or multiples on an ounce basis, but gold is more exotic. Only the 1 ounce gold bar has actually prevailed on the market.

Worth mentioning are the 400-ounce gold bars, also known as "Good Delivery" bars. That translates to almost 12.5 kg of pure gold. Thus, a value that is unlikely to be affordable for very few private investors.

Also worth mentioning in the case of silver are the 1000 ounce silver bars. However, with the equivalent of over 31 kg, these already have a considerable weight.

Value of troy ounce of gold in euros
Value of troy ounce of gold in dollars

Where is the best place to buy 1 ounce of gold?

On GOLD.DE, Germany's largest comparison portal for precious metals, you can compare prices, products or dealer reviews online and then select the best offer.

In addition, all dealers listed in the GOLD.DE price comparison bear the "GOLD.DE-certified" seal. It ensures the best possible security when buying gold. More: The GOLD.DE seal

Difference between troy ounce and fineness

The troy ounce is an absolute measure of weight, i.e. an indication in grams. In contrast to this, the fineness is a relative measure of weight and means the proportion of pure precious metal in any total weight, expressed in per mille.

Examples of such percentage values: 333 gold, 585 gold or 999 gold. The latter would be practically pure gold. More: Fineness and carat - simply explained

Rough weight and fine weight

The rough weight (formerly: rough weight) describes the total weight of an alloy in precious metals. The fine weight, on the other hand, means the pure proportion of the most valuable precious metal, expressed in troy ounces or grams

Information in troy ounces relates exclusively to pure precious metal. For example, the 1 oz Krugerrand contains exactly 1 ounce of pure gold, i.e. 31.1034768 grams, but the total weight is higher. The reason is that around 2.83 grams of copper are added to the Krugerrand.

So the 1 ounce Krugerrand is a gold alloy. Therefore, the rough weight is higher than the weight of the troy ounce of gold it contains. The total weight of the 1 ounce Krugerrand is around 33.93 grams, but the 2.83 grams of copper additions are practically irrelevant to the price.

Gold coins can therefore have different gold proportions up to 999.9 per thousand, which is practically pure gold. The following applies only to 999.9 gold coins: 1 ounce of gold = total weight of the coin. However, 999.9 coins are sensitive to scratches because pure gold is very soft. More: gold alloys


Gold coinalloyFine weightGross weightMaterial hardness
Vreneli900 per mille5.8 g6.5 gvery hard
Krugerrand916.6 per mille31.1 g33.9 ghard
Ducats986 per mille3.4 g3.5 gsoft
Maple Leaf999.9 per mille31.1 g31.1 gvery soft
Weights rounded

Gold bars almost always have a gold content of 999.9 per mille.

Conversion table ounce - gram

Ounces worthin grams (rounded)in grams (exactly)
1/50 oz0.6 g0.622069536 g
1/20 oz1.6 g1.55517384 g
1/10 oz3.1 g3.11034768 g
1/8 oz3.9 g3.8879346 g
1/4 oz7.8 g7.7758692 g
1/2 oz15.6 g15.5517384 g
1 oz31.1 g31.1034768 g
2 oz62.2 g62.2069536 g
5 oz155.5 g155.517384 g
10 oz311.0 g311.034768 g
12 oz373.2 g373.2417216 g
400 oz12.4 kg12,441.39072 g
1000 oz31.1 kg31,103.4768 g

Use the ounce to gram weight converter