Understanding Troy Ounces to Carats Conversion
The troy ounce (ozt) is the standard mass unit for trading precious metals such as gold, silver, and platinum, equal to about 31.10 grams. The metric carat (ct) is the mass unit for gemstones and pearls, fixed at exactly 200 milligrams. Converting between them is useful when a single object combines bullion and gemstones, such as jewellery, or when comparing precious-metal and gemstone weights on a common scale.
Conversion Formula
To convert Troy Ounces to Carats, multiply by this factor:
Step-by-Step Example
Convert 25 Troy Ounces to Carats.
How to Convert Troy Ounces to Carats
Use the exact factor of 155.5174 carats per troy ounce.
- Identify the input: Note the troy-ounce value: identify the mass you want to convert, expressed in troy ounces (ozt).
- Multiply by the factor: Apply the factor: multiply the troy-ounce value by 155.5174 to get carats.
- Read the result: Read the result: the product is the equivalent mass in carats (ct).
- Worked example: For 25 troy ounces: 25 x 155.5174 = 3887.94 ct.
Troy Ounces to Carats conversion table
| Troy Ounces (ozt) | Carats (ct) |
|---|---|
| 0 | 0 |
| 1 | 155.5174 |
| 2 | 311.0348 |
| 3 | 466.5522 |
| 4 | 622.0695 |
| 5 | 777.5869 |
| 6 | 933.1043 |
| 7 | 1088.622 |
| 8 | 1244.139 |
| 9 | 1399.656 |
| 10 | 1555.174 |
| 15 | 2332.761 |
| 20 | 3110.348 |
| 25 | 3887.935 |
| 30 | 4665.522 |
| 40 | 6220.695 |
| 50 | 7775.869 |
| 60 | 9331.043 |
| 70 | 10886.22 |
| 80 | 12441.39 |
| 90 | 13996.56 |
| 100 | 15551.74 |
| 150 | 23327.61 |
| 200 | 31103.48 |
| 250 | 38879.35 |
| 300 | 46655.22 |
| 400 | 62206.95 |
| 500 | 77758.69 |
| 600 | 93310.43 |
| 700 | 108862.2 |
| 800 | 124413.9 |
| 900 | 139965.6 |
| 1000 | 155517.4 |
| 2000 | 311034.8 |
| 3000 | 466552.2 |
| 4000 | 622069.5 |
| 5000 | 777586.9 |
| 10000 | 1555174 |
| 25000 | 3887935 |
| 50000 | 7775869 |
| 100000 | 15551740 |
| 250000 | 38879350 |
| 500000 | 77758690 |
| 1000000 | 155517400 |
What is the Troy Ounce?
The troy ounce is a unit of mass used almost exclusively for precious metals such as gold, silver, platinum, and palladium. It is the standard weight quoted on global bullion markets.
Definition
The troy ounce is defined as exactly 480 grains, which equals 31.1034768 grams:
By definition, 1 troy ounce = 480 grains = 31.1034768 g exactly, and 12 troy ounces make one troy pound (≈373.242 g). Note that the troy ounce is heavier than the more familiar avoirdupois ounce (≈28.3495 g).
Origin and History
The troy system takes its name from the French market town of Troyes, a major medieval trading hub. It descends from the Roman monetary system and was standardized in England for coinage and precious metals, later adopted across Europe and the English-speaking world.
Law and Notable Facts
The troy ounce remains the legal basis for bullion trading and coinage weights; in the United States it is codified for precious-metal transactions. A curious consequence is that a pound of gold (troy, ~373 g) actually weighs less than a pound of feathers (avoirdupois, ~454 g).
Real-World Examples and Conversions
A standard Good Delivery gold bar weighs about 400 troy ounces (≈12.4 kg). A 1 oz American Gold Eagle contains one troy ounce (31.1 g) of gold. When gold is quoted at "$2,000 per ounce," that means per troy ounce, not the avoirdupois ounce.
What is the Carat?
The carat is a unit of mass used to weigh gemstones and pearls. It should not be confused with the "karat," which measures gold purity.
Definition
The metric carat is defined as exactly 200 milligrams:
That is, 1 carat = 200 mg = 0.2 g exactly. Each carat is further divided into 100 "points," so a 0.25 ct stone is called a 25-point diamond.
Origin and History
The word derives from the carob seed (Greek keration), historically used as a counterweight in balancing scales because its mass was thought to be remarkably consistent. To end regional variation, the metric carat of exactly 200 mg was adopted internationally in the early 20th century, around 1907–1914.
Law and Notable Facts
The metric carat is legally recognized in most countries for the gem trade. A common misconception is that carat measures a diamond's size; it actually measures mass, so two stones of equal carat can look different depending on cut and shape.
Real-World Examples and Conversions
A typical engagement-ring diamond is around 1 carat (200 mg). The Hope Diamond weighs about 45.52 carats (≈9.10 g). Five carats equal exactly one gram.
Frequently Asked Questions
How many carats are in a troy ounce?
A single troy ounce equals 155.5174 carats, because one troy ounce is 31.10348 grams and each carat is exactly 0.2 grams.
Is the carat here the same as gold karat?
No. The metric carat (ct) is a unit of mass for gemstones, while gold karat (K) describes purity as parts out of 24. This conversion only concerns mass.
How do I convert carats back to troy ounces?
Multiply the carat figure by 0.006430149. For example, 500 ct equals about 3.215 troy ounces.
Where is this conversion used?
It is handy in jewellery appraisal and auction cataloguing, where a piece may list its gold content in troy ounces and its set stones in carats.
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Complete Troy Ounces conversion table
| Unit | Result |
|---|---|
| Micrograms (mcg) | 31103480 mcg |
| Milligrams (mg) | 31103.48 mg |
| Grams (g) | 31.10348 g |
| Kilograms (kg) | 0.03110348 kg |
| Metric Tonnes (mt) | 0.00003110348 mt |
| Carats (ct) | 155.5174 ct |
| Ounces (oz) | 1.097143 oz |
| Pounds (lb) | 0.06857143 lb |
| Stones (st) | 0.004897959 st |
| Tons (t) | 0.00003428571 t |
| Long Tons (long-ton) | 0.00003061224 long-ton |
| Grains (gr) | 480 gr |
| US Hundredweights (cwt-us) | 0.0006857143 cwt-us |
| UK Hundredweights (cwt-uk) | 0.0006122449 cwt-uk |
| Slugs (slug) | 0.002131265 slug |