Nepedia
Back to Discover
Fluent Reader
⚛️

Troy weight

physical science Maturity 11-13 Next article →

Troy weight is a special system used to measure mass. It is most common in the trade of precious metals. People use it to weigh things like gold and silver.

Gold1oz
Gold1oz

The most famous part of this system is the troy ounce. One troy ounce weighs about 31.1034768 grams. This is heavier than a standard ounce used for other goods.

comparison of pounds
comparison of pounds

This system helps traders be very exact with valuable items.

This system has several different parts that work together. The smallest unit is the grain. There are 480 grains in one troy ounce.

Ingots of Ge, Fe, Al, Re, Os, one troy ounce each (2)
Ingots of Ge, Fe, Al, Re, Os, one troy ounce each (2)

Next, you have the pennyweight, which is written as dwt. One pennyweight is equal to 24 grains. It takes 20 pennyweights to make a single troy ounce. Finally, there is the troy pound. A troy pound is made of 12 troy ounces.

No one knows exactly how this system started. Many people think the name comes from Troyes. Troyes is a market town in France. English merchants traded there a long time ago.

TroyPoundEngraving
TroyPoundEngraving

Another idea comes from the word "troi." This word might mean a balance or a place for weighing. Some say it comes from how people weighed precious goods. It is different from the way people weighed coal or corn.

History shows how these weights changed over many years. The Romans used bronze bars as money before they had coins. One of these bars was called a pound. An ounce was one twelfth of that pound. In England, troy weights became official for gold and silver in 1527. The United States also adopted the troy ounce for its coins in 1828.

1000oz.silver.bullion.bar.underneath
1000oz.silver.bullion.bar.underneath

This helped make sure money was the same weight everywhere.

You can see how these units connect to your world. Doctors once used the troy system for medicine. This was known as the apothecaries' system. Most people use the metric system for medicine today. However, the troy ounce is still used in metal markets. Even in places that use the metric system, traders use it. It is a very old way to measure the treasures of the earth.

344 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (5)
File:Gold1oz.jpg
Gold1oz.jpg
File:Ingots of Ge, Fe, Al, Re, Os, one troy ounce each (2).jpg
Ingots of Ge, Fe, Al, Re, Os, one troy...
File:1000oz.silver.bullion.bar.underneath.png
1000oz.silver.bullion.bar.underneath.png
File:comparison of pounds.svg
comparison of pounds.svg
File:TroyPoundEngraving.jpg
TroyPoundEngraving.jpg
More to explore

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.