Gold has been considered a valuable metal for centuries, with its rarity and lustrous beauty making it a prized commodity. When evaluating and trading quantities of gold, there are some key measurements to understand, including troy ounces and pounds. So how many troy ounces of gold does it take to make a pound?
Quick Answer
There are 12 troy ounces in a troy pound of gold. Given that a troy ounce is equivalent to 31.1034768 grams and a troy pound is equivalent to 373.2417216 grams, there are 12 troy ounces in a troy pound since 31.1034768 x 12 = 373.2417216.
What is a Troy Ounce?
A troy ounce is a unit of measurement commonly used for precious metals like gold, silver, platinum, and palladium. It is different from the avoirdupois ounce commonly used in the United States and elsewhere for weighing everyday items.
The key differences between a troy ounce and avoirdupois ounce are:
- A troy ounce equals 31.1034768 grams, while an avoirdupois ounce equals 28.3495231 grams.
- A troy ounce weighs about 10% more than an avoirdupois ounce.
- Troy ounces are primarily used for precious metals, while avoirdupois ounces are used for everyday goods.
The troy ounce’s origins trace back to the Middle Ages in Troyes, France, which was an important market town. The troy weight system was adopted in England during the reign of King Henry VIII. It became the official system for weighing gold and silver in the British Empire and the United States.
While metric measurements are common today, the troy ounce is still the standard unit of measure for precious metals in the U.S. and globally. The price of gold and silver are still quoted in troy ounces.
What is a Troy Pound?
A troy pound is a unit of weight equivalent to 12 troy ounces. It is part of the troy system of measurement. Given that one troy ounce equals 31.1034768 grams, a troy pound equals 373.2417216 grams (12 x 31.1034768 g).
A troy pound is approximately 10% heavier than the more widely used avoirdupois pound. While an avoirdupois pound equals 453.59237 grams, a troy pound equals 373.2417216 grams.
The troy pound serves as the standard unit of measure for gold, silver, platinum, and palladium in the precious metals industry. Refineries cast bars of these metals in troy pound sizes. The troy pound is also commonly used by jewelers when weighing precious metals.
Why Are There 12 Troy Ounces in a Troy Pound?
There are 12 troy ounces in a troy pound for historical reasons tracing back to the origins of the troy system of measurement. Dating back to the Middle Ages, the troy system was originally used just for weighing precious metals.
The pound was divided into 12 ounces under the troy system because it made calculations easier for minting coins. The troy system helped simplify dividing a pound of gold or silver into smaller coin sizes. Coin sizes were measured in “talents”, with each talent equaling 3000 troy grains. There are 24 troy grains in a troy pennyweight and 20 pennyweights in a troy ounce. Therefore, multiplying 24 x 20 equals 480 grains in a troy ounce. Multiplying 480 grains x 12 ounces equals 5760 grains in a troy pound.
This made it convenient when minting coins using precious metals. A talent of gold (3000 grains) could be minted into 125 pence. A troy pound (5760 grains) could be minted into 240 pence. The troy system provided straightforward ratios for dividing a pound into smaller coin sizes.
The convenience of having 12 troy ounces in a pound continues today. Precious metals like gold are still weighed in troy ounces and pounds.
Troy Ounce vs. Avoirdupois Ounce
While there are 12 troy ounces in a troy pound, there are 16 avoirdupois ounces in an avoirdupois pound. The avoirdupois system is the everyday system of weight commonly used in the United States, Canada, and the UK for measuring items other than precious metals.
An avoirdupois ounce weighs 28.3495231 grams, around 10% less than the 31.1034768 grams in a troy ounce. With 16 avoirdupois ounces equaling 453.59237 grams, the avoirdupois pound is lighter than the troy pound.
Below is a comparison of key measurements between the troy and avoirdupois systems:
| Unit | Troy | Avoirdupois |
|---|---|---|
| Ounce | 31.1034768 g | 28.3495231 g |
| Pound | 373.2417216 g | 453.59237 g |
The differing ounces and pounds between the two systems can cause confusion when converting between units or comparing weights. Paying attention to whether troy or avoirdupois units are being used is important for accurate conversions.
Converting Troy Ounces to Pounds
To convert from troy ounces to troy pounds, simply divide the number of troy ounces by 12, since there are 12 troy ounces in a pound. For example:
- 1 troy ounce = 0.083 troy pounds
- 24 troy ounces = 2 troy pounds
- 48 troy ounces = 4 troy pounds
Converting from troy pounds to ounces is done by multiplying the number of pounds by 12.
- 1 troy pound = 12 troy ounces
- 2 troy pounds = 24 troy ounces
- 4 troy pounds = 48 troy ounces
Converting Between Troy and Avoirdupois
Converting between the troy and avoirdupois systems requires paying close attention to the different ounce and pound sizes.
To convert troy ounces to avoirdupois ounces, multiply the troy ounces by 1.09714285. For example:
- 12 troy ounces x 1.09714285 = 13.165714 avoirdupois ounces
- 24 troy ounces x 1.09714285 = 26.331429 avoirdupois ounces
To go from avoirdupois ounces to troy ounces, multiply the avoirdupois ounces by 0.91145834. For example:
- 16 avoirdupois ounces x 0.91145834 = 14.583334 troy ounces
- 32 avoirdupois ounces x 0.91145834 = 29.166668 troy ounces
For pounds, multiply the troy pounds by 1.2 to get avoirdupois pounds. Multiply avoirdupois pounds by 0.833333 to get troy pounds.
Key Facts
To summarize some of the key facts covered:
- A troy ounce equals 31.1034768 grams.
- A troy pound equals 373.2417216 grams.
- There are 12 troy ounces in a troy pound.
- The troy system is used for weighing precious metals.
- The avoirdupois system is used for weighing everyday items.
- Troy ounces weigh 10% more than avoirdupois ounces.
- Careful conversions are required when switching between troy and avoirdupois units.
Applications
Understanding troy weights is essential for anyone working with precious metals or doing jewelry work. Some examples of how troy pounds and ounces are used include:
- Gold investing and trading – The price of gold is quoted in troy ounces. Calculations involving the value of gold holdings or transactions require conversions between troy ounces and pounds.
- Jewelry making – Precious metals used in jewelry work are measured in troy ounces. Jewelers must understand troy weights when alloying or working with gold, silver, platinum etc.
- Coin collecting – The gold and silver content of coins is measured in troy ounces. Coin weight and purity determinations depend on troy measurements.
- Precious metals refining – Refineries cast gold and silver bars in troy ounce and pound sizes. Accurately calculating precious metal quantities relies on the troy system.
In these and other applications involving precious metals, not having a proper grasp of troy weights can lead to costly mistakes and errors.
Calculations
Let’s go through some examples of calculations involving troy ounces and pounds:
Price Calculations
If the price of gold is $1500 per troy ounce, how much is 25 troy ounces of gold worth?
- 25 troy oz x $1500 per troy oz = $37,500
If gold is priced at $2000 per troy ounce, what is the value of 12.5 troy pounds?
- 12.5 troy lb x 12 troy oz/lb = 150 troy ounces
- 150 troy oz x $2000 per troy oz = $300,000
Weight Conversion Calculations
How many avoirdupois ounces are there in 14 troy ounces?
- 14 troy oz x 1.09714285 avoirdupois oz/troy oz = 15.36 avoirdupois oz
If a gold bar weighs 8 troy pounds, what is its weight in avoirdupois pounds?
- 8 troy lb x 1.2 avoirdupois lb/troy lb = 9.6 avoirdupois lb
Purity Calculations
If a gold bar is .925 fine and weighs 10 troy oz, how many troy oz of pure gold does it contain?
- 10 troy oz x 0.925 purity = 9.25 troy oz pure gold
A silver coin is .999 fine and weighs 1 troy ounce. What is the coin’s actual silver content?
- 1 troy oz x 0.999 purity = 0.999 troy oz silver
Conclusion
In summary, there are 12 troy ounces in a troy pound when weighing gold, silver, platinum and other precious metals. This is a result of the troy system’s origins being designed around making coinage calculations straightforward. While imprecise conversions between units can work in everyday life, understanding troy weights is vital for accurately working with precious metals. Taking the time to learn the specifics of the troy system, including how it differs from avoirdupois weights, will save headaches down the road.
