How Many Grams Are In An Ounce of Gold?

It’s difficult to keep up with measurements and weights when shopping for valuable metals like silver or gold. But it’s important to understand these measurements so you can shop responsibly and make informed decisions. So, how many grams are in an ounce of gold?

One ounce of gold is equal to 31.103 grams. This is because the unit of measurement use for valuable metals like gold, the Troy ounce, is different from the standard ounce. The troy ounce is slightly heavier than the standard ounce.

Read below as we discuss how many grams are in an ounce of gold and the difference between the two types of ounces.

How Many Grams Are in An Ounce of Gold?

An ounce of gold is equal to 31.103 grams. This is a bit of a head scratcher for those of us accustomed to the kitchen ounce (or standard ounce), which is equal to 28.35g. But allow us to explain. There are actually two different kinds of ounces: the ‘troy’ ounce and the ‘avoirdupois’ ounce.

The troy ounce is the measure of weight most frequently utilized in the industry of valuable metals, and it is the standard option for determining the weight of gold, silver, and platinum. It is frequently used in contexts related to the price of gold, which is typically expressed in terms of pounds, dollars, or euros per troy ounce.

The Origins of the Troy Ounce

The troy ounce was first established in Troyes, which is found in the Champagne area of France and is an old city with a rich history. The Knights Templar, for example, were founded there in the 12th century.

The city grew to become a popular place for commercial dealings as a result of its location at a hub on an extensive network of Roman routes. It was the site of the most major and extensive of all of the renowned Champagne Fairs throughout the Middle Ages. In this city, merchants from all over Europe converged in order to conduct business and trade their items, including wools, silks, leathers, furs, spices, and of course, rare gold and silver goods.

The Counts of Champagne, who became wealthy as a result of this endeavor, were responsible for the establishment of regulations that ensured the smooth running of the Fairs. It is stated that the city of Troyes is where the original method that was used to measure gold, silver, and jewels got its name.

At the conclusion of the 12th century, the troy system served as the foundation for a variety of monetary systems across Europe. It was during the reign of King Henry II (who ruled from 1154 to 1189 and was known as the Angevin ruler because he also ruled considerable regions in France) that it arrived in Britain.

English pennies weighed exactly 1/240th of a troy pound of sterling silver, which corresponded to their value of 1/240th of a pound sterling. There were 20 ‘pennyweights’ within a single troy ounce, therefore one troy pound was equal to 12 troy ounces.

It is still common practice to weigh precious metals using troy weights, even though avoirdupois weights (wherein one pound equals 16 ounces) are becoming increasingly common for items of a more general nature.

Troy pounds and pennyweights went out of fashion in the 19th century, but even when British legislation in 1963 destroyed other archaic measurements and weights, the troy ounce survived for trading in valuable metals.

Difference Between Standard Ounce and Troy Ounce

When talking about the world of precious metals, it is essential to understand the difference between the phrases “troy ounce” and “ounce.” Despite the fact that they may appear to be synonymous, their origins in history are quite different, and they are used in quite different ways today.


An ounce is a standard unit of measurement that can be applied to the calculation of a wide range of different quantities, such as mass, volume, and weight. In the United States, this is the unit of measurement that is considered to be the standard, and it is equal to 28.35 grams. 

When dealing with precious metals like gold and silver, the troy ounce is the standard unit of measurement. The troy ounce is a classic unit of weights and measures that is characterized by its higher weight in comparison to the standard ounce.


In the past, the troy ounce, served as the standard unit for measuring precious metals throughout Europe. The standard ounce, on the other hand, was designed as a more generic measurement of weight and was applied in the measuring of common things like food and other items.

Weight and Other Variables

It is important to be aware that the troy ounce has a weight that is marginally higher than that of the standard ounce. The troy ounce is equal to 1.09 standard ounces and weighs 31.103 grams, whereas one ounce equals 28.34 grams.

When dealing with huge numbers of precious metals, this seemingly insignificant difference in weight can turn out to be significant since it may lead to a difference in value. Furthermore, it is important to have a working knowledge of the conversion rate, as one ounce corresponds to 0.91 troy ounces and one troy ounce is the same as 1.09 ounces.

Quality of Purity in Valuable Metals

The difference in weight between the two measurements has an effect, not only on the value of the precious metals, but also on their purity. If we take the example of a gold bar labeled “999.9 pure,” for instance, it would in fact be 99.99% pure gold if weighed in troy ounces, but it would only qualify as 99.99% pure gold when weighed in ounces.

Why Does This Difference Matter?

If you are basing the pricing of your gold bullion on standard ounces rather than troy ounces, then your calculations will be wrong by around ten percent. This represents a significant variation in gold weights throughout the industry, which will have an impact on the overall worth of the product.

When somebody says “how many ounces?” their question is actually referring to “how many troy ounces?” since the industry utilizes Troy ounces as the accepted measuring system. This can lead to some confusion because “ounces” is a more common term.

When making price comparisons involving gold and its various sizes, it is essential for investors to have a solid understanding of the quantity of gold they are dealing with at any one time. This could also be useful for calculating the best costs for various things, particularly if you are comparing products that are measured in grams with those that are measured in Troy ounces.

For example, beginning in 2016, Chinese Gold Panda coins have had their weights denoted in grams. Avoid making the common mistake of converting to avoirdupois ounces while shopping for coins based on the Troy ounce standard.


Buying gold can be expensive; whether for jewelry or investments. And now that you know about the exact type of ounce used for measuring gold and how many grams it equals, you can continue to shop for gold more responsibly and in an informed way.

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