Shop Acre Gold from $50

How Many Grams Are in an Ounce of Gold?

How Many Grams Are in an Ounce of Gold?

Gold is one of the most attractive precious metals and is highly valued. Not only does it have a lavish, bright color, but it’s also weighty, giving it a luxurious feel. 

When purchasing or selling gold, you need to calculate its weight in grams and ounces. Make sure to use the correct type of ounce. There are a handful of ounces to choose from, including fluid ounce, avoirdupois ounce, and troy ounce. 

The Weight Measurements of Gold 

Gold is weighed and measured using different types of measurement units. The unit used depends on what you want to measure. For example, if you simply want to know how much the gold weighs, you would use grams or troy ounces. But, if you want to learn more about its purity or fineness, you use karats or Millesimal fineness.

Gold in Grams

Market values are listed by troy ounce and by grams. The term gram comes from the Latin word “gramma,” meaning small weight. Have a paper clip or a pen cap handy? If not, visualize one. Their weight individually is about a gram, very light. 

If you are to compare a gram to a troy ounce, you have .0321507. What’s a troy ounce? The preferred unit of weight measurement for precious metals.

Gold in Troy Ounces

It’s important to differentiate between a troy ounce and a regular ounce. A troy ounce does not carry the same value of measurement. Think about the last time you went to the grocery store and purchased sugar or grains. The proper term for a regular ounce is avoirdupois ounce (oz), but no one commonly uses that name. You recognize a regular ounce as 16 ounces or 28.35 grams. On the other hand, one troy ounce is equal to 1.09 ounces, or 31.10 grams.

The troy ounce is the primary measurement of weight, or mass, of precious metals and stones. It is believed to have originated from a French Town known as Troyes in the Middle Ages. Merchants from all over the world would come to Troyes to buy and sell their goods, so in turn, a standardized weight system would benefit them and the rest of the world as business transactions are conducted.

The troy ounce serves as an approved international unit of measure. Equally across the globe, buyers and sellers of gold have a central method of knowing if gold is pure and if weight standards are met through this unit of measurement. 

There is no other use for the troy ounce except to price gold, silver, and platinum. Before buying gold or selling gold, verify that the gold’s weight is measured in troy ounces and not regular ounces. Troy ounces can weigh 10 percent more, making a huge difference in price, especially if the transaction is in bulk.


To settle a debate, which one do you associate with gold: karat or carat? If you guess karat, you are correct. A karat (with a “k”) measures the purity of gold, whereas a carat (with a “c”) measures the weight of precious stones such as diamonds, emeralds, pearls, etc. It’s easy to get the two terms confused.

Quick history lesson: The term karat derives from the Arabic and Greek word meaning “the fruit of the carob tree.” The seeds of the carob tree were once used as a unit of measurement for gold and jewelry. It was believed that their mass distribution had no variance; however, that is not a true statement. Their weight and size vary dramatically.

When purchasing gold, whether it is a gold bar, coin, or jewelry, it is measured using karats (k). Karats range on a scale from 0 to 24, representing 1/24 parts. The lower the karat, the lower the purity. What does that mean? Well, if you have a gold piece that is 10k, it means that 10 parts of it contain gold. The other 14 parts include another type of alloy ranging from silver, copper, platinum, etc. These metals help harden the gold since pure gold is soft.

Twenty-four-karat gold is the purest gold. It’s sometimes used to craft jewelry, but it’s reserved for gold bars and coins. Part of the reason is that at this level of purity, it is the softest. Handle it with care to avoid bumps or scratches. It is also the most expensive and deters people from having interest and purchasing. The color of 24 karat gold is beautiful, though, showing very bright yellow and orange colors.

So, where does the number 24 come from? This dates back to the ancient Romans when they minted a coin known as the solidus was minted. It weighed 1/72 libras (the Roman pound). The weight of the solidus coin was equivalent to 24 silver siliqua coins. From our quick history lesson, the seed of the carob tree was used as a system of measurement. Guess what? Siliqua refers to that seed from ancient Greek times. Thus, the karat system became connected with the number 24.

Millesimal Fineness 

Karats and millesimal fineness go hand in hand when measuring gold purity. Millesimal fineness measures the purity on a different system, comparing it to impurities or other alloys in parts per thousand.

Sticking to the scale of 10k, 12k, 14k, 18k, and 24k gold (when measured in karats), the millesimal fineness measures 417, 500, 583, 750, and 999. Be mindful of these numbers. Should you find a millesimal fineness of 800, 925, or 950 on a gold piece, heed caution -- it’s likely silver plated with gold.

Both karats and millesimal fineness are stamped on gold pieces. Look out for the hallmark so that you know what you are investing in.

Gold Measurements Across the Globe 

The purpose behind troy ounces is to stay consistent, wherever you are from North America to Europe. However, that is not always the case. For example, in Southeast Asia, the tola is the preferred system of measurement. In China, it is tael or tahil. And in Thailand, the baht. Each of these converts grams and ounces differently.

Regardless of the type of measurement, do your research and become familiar with the weight of your gold. Avoid the risk of a loss of investment.

There are additional measurements used when the quantity of gold traded is small. This includes grains and pennyweights.

Gold in Grains 

Grains of gold are exceptionally small. To compare to grams and ounces, one grain of gold equals .065 grams and .00208 troy ounces. 

Buying gold in grains is a popular choice, though, especially for new investments. Collectors also admire it. There is a level of control that the buyer has over gold at this size. It also makes a very nice gift during the holiday season. But size does not matter when it comes to the overall price of gold. The price does continue to be affected on a day-to-day basis, depending on the market.

Gold in Pennyweights

The pennyweight (dwt) is a descendant of the troy ounce. In the 15th century, the English penny weighed 1/20th of a troy ounce, meaning there are 20 pennyweights in 1 troy ounce. A pennyweight also converts as 1.55 grams and 24 grains.

When is a pennyweight unit of measure used? It’s most commonly used in dentistry and by jewelers. Don’t be fooled by the size of gold in pennyweights. It is still valuable; it’s gold after all.

Weighing Tools and Resources

Ready to weigh your gold or test its purity? You can use tools available in your own home, or you can seek out services from a professional.

Gold is weighed using digital gram scales. Most scales provide options to weigh at pennyweights, grams, and ounces.

For purity tests, gold testing kits and karatmeters are at your disposal. Gold testing kits include multiple test solutions that help you identify the number of karats in your gold. A karatmeter acts as an x-ray and can be expensive. Its results are quick, retrievable in thirty seconds, and accurate.

Jeweler’s loupes are another option, as long as you know how to use them and what to look for. They act as a magnifying glass, allowing you to look for cracks, blemishes, etc. 

The Bottom Line 

Gold is primarily measured using an international unit of measurement known as the troy ounce; however, it may differ depending on where it is purchased from. Be familiar with the unit of measurement used and the purity level before making any type of investment decision. Both factors have a direct effect on the value of gold.

You can begin investing in gold easily and affordably with Acre Gold. Get gold delivered to your door and get started investing today!



Price of gold per troy ounce 2020 | Statista

How Many Grams in an Ounce - Grams to Ounces |

The historic roots of the troy ounce standard of measure | Provident

What is a carat, and how does it relate to a karat? |

The History of Measurements |

Pennyweight Calculator & Conversion Calculator - Manhattan Gold & Silver | MGS Refining