Ounce Vs Troy Ounce - What's the Difference?

A Common Misconception Between Ounces and Troy Ounces

One of the biggest misconceptions for investors who are new to the bullion marketplace is to think that an ounce and a troy ounce are equal. This is not the case, and many people are frequently confused when their products weigh more than one regular ounce (avoirdupois ounce). In fact, most products are referred to in ounces but are actually sold in troy ounces. The reality is that the vast majority of bullion dealers are referring to troy ounces when they say "ounces". This is the "industry standard."

History Of The Troy Ounce and The Troy Weight

Theories regarding the origin of the Troy weight system could never reach a precise conclusion. However, the most accepted assumption is that it originated in the French city of Troyes in the Middle Ages. Merchants from the local markets felt the need to establish a standard unit for precious metal products that would differentiate it from common measures used to buy and sell goods at the time.

At some time during the Middle Ages, different versions of Troy weights coexisted around Europe, including the Holland troy and the Paris troy, with slight differences. But none would stand out as much as the British troy weight system.

During the reign of King Henry V in the 1400s, the troy system was already largely in use around Britain. In 1527, England officially adopted the troy ounce as the measurement unit for gold and silver and the British coinage system. The Troy system was Later, in the 19th century, when they established the British Imperial system of weights and measures (or simply the Imperial units, for short), the troy ounce was incorporated.

From that point on, it isn't difficult to deduce why the Troy ounce became the standard unit for precious metal products in many countries around the world. The British Empire colonized and incorporated a lot of territory into their Commonwealth during the Age of Discovery. It is no wonder that those colonized countries, even after their independence, retained cultural aspects and customs. And the use of Troy ounces for measuring precious metal items such as gold, silver, platinum, and palladium, was definitely one of those. The United States, for instance, officially adopted the British Imperial Troy ounce by an Act of the US Congress in 1828.

The Troy weighting system includes the troy grain, the pennyweight (24 troy grains), the troy ounce (20 pennyweights), and the troy pound (12 troy ounces). Whereas the troy grain is equal to its namesake of the avoirdupois system, the troy ounce is slightly heavier than the avoirdupois ounce. The troy pound, on the other hand, is lighter than the avoirdupois pound.

The Difference Between The Two Ounce Units

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Avoirdupois Ounce (oz): 28.3 grams

Troy Ounce (Troy oz): 31.1 grams

A troy ounce weighs about 10% more compared to an ounce, which makes a big difference when it comes to precious metals.

1 Troy ounce = 1.097 ounce

Besides the obvious weight differences, there is another distinction in the way they are measured. Everyone knows that 1 oz = 1/16 lb, so a troy pound must be heavier right? Contrary to popular belief, it's not. In the Troy system, a troy pound is actually only equal to 12 troy ounces, which ends up being lighter. Thus, in terms of weight, 1 pound of silver is approximately 80 grams more than 1 troy pound of silver. For that reason, most bullion being traded and sold is measured in troy ounces or kilograms. This is to avoid any confusion between the conversions between troy ounces and troy pounds.

Check out our posts:

How many Grams In an Ounce of Silver?


How Many Grams Are In An Ounce of Gold?

The Importance of Buying In Troy Ounces

Troy Ounce - Silver Round

It is important to be aware of what you are buying because certain unverified dealers will sell precious metals in ounces instead of troy ounces. This small difference can make one product look like a much better deal. Don't be fooled, though. If you know and trust your source for bullion, this deception is rare and not likely something you would have to worry about.

The best way to make sure it is in troy ounces is to buy products with their weight and purity standards engraved on them. This practice is very common in the industry. Nevertheless, in the case that a bullion product, such as a silver round or gold bar does not have the weight & purity engraved on it, it may be hard to liquidate it down the road. Another option is to buy government minted products, such as a silver coin or gold coin. Most government mints will produce bullion in troy ounces. A notable exception is the Chinese Mint since their recent adoption of the metric system and gram weights as the unit of measure for their bullion coins.

Buy Bullion In Troy Ounces At SD Bullion

To avoid pitfalls and possible scams, make sure to purchase your bullion from trusted precious metals dealers only. SD Bullion is an Inc. 500 company that has been in the business since 2012. Since then, we have amounted to over 250,000 online customers. Our products are only sourced from the best manufacturers in the business. We carry products of both systems of weights, as specified by the producer, to satisfy the needs of all prospective buyers.

Find great deals on gold, silver, and platinum products at the lowest premium over their spot price. If you would like to find out more about the items we have in stock, talk to us over the phone at 1(800)294-8732 or through our live webchat. You can also send us an email at sales@sdbullion.com. We are available from Mondays to Thursdays, from 8 am to 6 pm EST, and on Fridays from 8 am to 5 pm EST.

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Chris Keller
Chris Keller
Product Specialist

Chris Keller has a passion for the precious metals industry (he's been collecting coins since he was a child). He specifically enjoys creating written and video content around unique products that our customers might not see otherwise. At SD Bullion, Chris has consulted thousands of bullion investors leading to millions of dollars in sales.