How Many Grams In an Ounce of Gold?

Gold jewelry and gold bullion weights are what determines their prices. Gold is typically measured in grams or troy ounces, depending on where you buy it. So, it is crucial to know how many grams is an ounce of gold. You should also keep in mind there are two types of ounces, the imperial ounce and troy ounce, and they don’t weigh the same.

That can be a little confusing for those who enter the gold market for the first time. When you hear about an ounce of gold, you need to know that it means a troy ounce of gold, not dry and liquid ounces you use in everyday life.

Imperial Ounce vs. Troy Ounce

Imperial ounce

The imperial (avoirdupois) ounce is a unit you usually use to measure everyday stuff. For instance, you will use imperial ounces when buying groceries, especially bulk dry goods. All recipes from cookbooks also contain measurements in imperial ounces.

The name avoirdupois comes from the French word avoir de pois, meaning goods of weight or property. Nowadays, ounce belongs to the traditional weight measurement of the British Imperial System and the US Customary System that use pounds and ounces as units of mass.

Another reason for the term imperial ounce is that it is a part of the United Kingdom’s imperial measurement system. The British used it to measure various trading goods. This imperial (avoirdupois) system spread to America after settling a new continent, and people still use it for their everyday needs.

Troy ounce

It is believed that the troy ounce got its name after Troyes, an old trading market in France where it was initially used. It was accepted as a central market, so their measurement system became a standard for merchants from various regions to communicate and make trading deals.

The troy system became an official measuring unit for precious metals, like gold, platinum, silver, palladium, and rhodium in the 16th century.

However, there are indications it existed even before that, in ancient Rome. Considering that, the troy system is one of the oldest known measuring systems that manufacturers, sellers, and buyers still use today.

Remember that you need to use troy ounces for measuring precious metals’ weight, never imperial ounces. It is essential because of the difference in weights, no matter how small it is.

Calculating the Gold Weight in Grams

The origin of the term gram is in the Latin word gramma, meaning small weight. That is exactly what grams are good for since they precisely determine small amounts of gold.

If you are familiar with the metric system, you probably know that 1 ounce equals 28.35 g. However, the troy ounce weighs more or precisely 31.1 g. It is equal to 480 grains, which is one more common measuring unit for gold.

In case you need a closer comparison, one gram is approximately the weight of a paper clip. On the other hand, a new wooden pencil weighs one ounce, the same as 28 paper clips.

If you want to express a troy ounce in these everyday objects, you can consider it equal to 31 paper clips. You can always compare these objects you probably have at home to feel the difference between a gram and an ounce in your own hands.

Importance of Ounces and Troy Ounces Differentiation

The difference between 28.35 and 31.1 grams doesn’t seem like much at first glance. In fact, the troy ounce is only about 1.1 times larger than the regular ounce. Therefore, the question is why it is a big deal what kind of ounces you use.

For a start, even the tiniest variation in weight influences the price. One gram of pure gold costs $50 to $60, while you need to pay at least $1,700 to $1,800 per troy ounce. The final price will depend on the market’s location and current demand and supply.

Even though the difference between 28.35 g and 31.1 g is only 2.75, such a slight variation makes the price shift more than $100 when buying or selling this precious metal.

Comparison of the gold weight

Gram Ounce Troy ounce
1 g 1 oz 0.9 ozt
5 g 1.09 oz 1 ozt
10 g 0.035 oz 0.032 ozt
28.35 g 0.17 oz 0.15 ozt
31.1 g 0.35 oz 0.32 ozt
50 g 1.76 oz 1.6 ozt
100 g 3.52 oz 3.2 ozt
200 g 7.05 oz 6.42 ozt
300 g 10.58 oz 9.64 ozt
400 g 14.11 oz 12.86 ozt
500 g 17.63 oz 16.06 ozt
1,000 g (1 kg) 35.27 oz 32.14 ozt
12,441.19 g (12.4 kg) 438.85 oz 400 ozt

Confusing standard ounces and troy ounces can make your calculations incorrect for approximately 10%. When dealing with gold, that miscalculating the weight can lead to money loss.

If you see the weight of gold in grams and have no clue what this weight means, you can quickly solve the problem. It will be enough to multiply that number by 0.03215 to get the gold weight in more familiar troy ounces.

Trading Gold

Fortunately, most gold bars and gold coins have their weight imprinted on the surface in both grams and ounces, which will save you the trouble of necessary calculating. Keep in mind that the mark sometimes only bears the measuring unit used in the country they originated in.

In some cases, gold bullion and coins have their weight imprinted neither in ounces nor grams but are made only in typical weights instead, making it easier to assess them.

For example, ounces and pounds are the primary mass units in most English-speaking countries. With that in mind, you will not have any problem determining the weight while trading gold in the US, the UK, Canada, Australia, and New Zealand.

On the other hand, all world countries, except for the US, Myanmar, and Liberia, use the metric system. However, the last two give their best to accept it.

Some countries in Asia like India, Singapore, Pakistan still prefer tola, while China and Japan use tael. Finally, Thailand uses baht. However, it is not the same since those are their local units for measuring, but these countries also work with the globally accepted metric system.

If you want to trade gold in some of the biggest gold markets in Europe and Asia, it is essential to understand the conversion of troy ounces and grams.

Gold bars

The most commonly found type of gold bar is the 400 troy ounces (12,4 kg) one, also known as the Good Delivery gold bar. It is a standard for gold investment, but it is not the most practical way of trading this precious metal. The reason is in small gold bars that can weigh as little as one gram.

These small bars are more convenient for keeping and trading because of their compact size. Also, selling one gram or one troy ounce of gold is much more practical than selling 100 or 400 troy ounces of this precious metal at once.

Beginners in trading are often more comfortable buying smaller amounts of gold because it is an affordable and less risky investment. For those purposes, gold bars that weigh 1 g to 10 g are their typical choice.

Gold coins

Gold coins, being much smaller than gold bars, can be more affordable due to their lesser weight. You can find coins that weigh from only 0.5 g to 50 g.

You can also find standard gold coins weighing one troy ounce (31.1 g). Some of the more famous ones of this kind are the Britannia, Canadian Maple Leaf, and Krugerrand.

Gold jewelry

When it comes to gold jewelry that you buy for its beauty instead of its investment value, it is a bit harder to determine its weight. That is because jewelry doesn’t have its weight imprinted on the surface like gold bullions.

Jewelry is also rarely made of pure gold, unlike gold bars and coins. Therefore, you need to know the gold percentage to determine its value accurately. Remember that the same principle for converting grams to troy ounces used for gold bars and coins applies here.

Reasons for Using Grams

Although almost everyone accepts the troy system for trading precious metals, there are some advantages of using the metric system and grams.

As I have already mentioned, a gram is smaller than a troy ounce, so it allows you greater precision in measuring. When you need to label a specific gold piece’s weight in troy ounces with decimals, it is more practical to express the same weight in whole numbers in grams.

For instance, it is more convenient to say that a gold bar weighs 1 gram than 0.032 troy ounces. Since such small gold bars are practical for smaller transactions, grams really come in handy for more precise calculating.


Comparing gold’s weight in grams and troy ounces doesn’t take more than simple math. However, you should remember that gold is always measured in troy ounces, not in ounces you usually use. While a regular ounce equals 28.35 g, a troy ounce has 31.1 g, and that difference significantly influences the price.

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