Troy Ounce vs. Ounce


Gold buyers use different forms of measurement when pricing your items. They consider the type of precious metal, the purity of the item and its weight. When it comes to the purity of the item, the karat is used to show how much gold an item is made of – for example 14K gold. A troy ounce measures its weight. But did you know a troy ounce is different than a regular ounce, which we use to measure ingredients when baking? Read more to learn about precious metal weight and get the most out of your jewelry, coins and other precious items when selling to a gold buyer.

What’s the difference between a troy ounce and an ounce (oz)

Since the Middle Ages, people have used the troy ounce to measure precious metals like gold, platinum, silver, and bronze. The name comes from Troye, France – where the measurement was first put into use by the city’s merchants. One troy ounce is equal to 31.1034768 grams. The abbreviation for this measurement is “t oz” or “oz t.”

The measurement we used for ingredients in the kitchen is also called an ounce – confusing, we know! This one is commonly referred to as a standard ounce, to show the difference between it and a troy ounce. A standard ounce weighs about 10% less than a troy ounce, equal to 28.35 grams.

Where did the troy ounce measurement come from?

In Troye, France where the troy ounce comes from, merchants from around the world came to sell and buy all types of items, including gold. At that time, 480 grains of barley equaled one troy ounce, and 12 troy ounces made up a troy pound. Romans also used a similar measuring system. Their measurement used bronze bars broken up into 12 “unica,” each one similar to an ounce. The unica also weighed about 31 grams.

The troy ounce measurement pre-dates the metric system now used across the world. It is one of the only measurements from long ago still in use by people today. The troy ounce was originally used to measure the weight of gemstones too, but today the carat is used around the world for measuring gemstones.

Why do they use troy oz vs. standard ounce?

Troy oz is considered an international standard of measurement and since precious metal is traded on a global market it has become a go-to standard. Bullion bars are also stamped and engraved with the weight in troy oz measurement and have been for hundreds of years.

Troy ounce conversion table

Here’s how the different measurements shape up when compared:

1 Troy Ounce

Standard Ounce










How gold buyers use the troy oz in pricing

If you are buying or selling gold or other precious metals, you can see why the difference between a troy ounce and a standard ounce matters in pricing. That’s because a troy ounce weighs nearly 10% more than a standard ounce. An item that weighs more has more precious metal which in turn will be worth more money. Other elements that play a factor in price are purity and the market price. An item that is higher in purity i.e. 24k gold, has more gold than 18k gold which, again, makes the item worth more money. Learn more about a Karat vs. Carat for selling your gold to a gold buyer. So, the more the item weighs and the higher the purity of an item is what gold buyers will look at when pricing your item.

Request a free appraisal kit today to see how much your precious metal items may be worth. As a national gold buyer, we will pay you the most for your gold items. Request your kit today!

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