Convert Troy ounces to Carats
1 troy ounce is 155.52 ct. One troy ounce is exactly 155.517384 carats.
One troy ounce is 155.51738 carats. To convert troy ounces to carats, multiply by 155.51738; to go the other way, divide by 155.51738 or multiply by 0.0064301493. The relation is exact but the figure is not: it is a rounding of a number that does not terminate, and it follows from NIST Handbook 44. Exactly 31.1034768 grams, and the only ounce bullion is ever quoted in.
Factor checked against the defining standard · How we check
- Troy ounces × 155.51738
1 * 155.51738155.517 ct
1 troy ounce in every weight unit
| Unit | Value | Exact factor |
|---|---|---|
| ounces | 1.097142857 oz | × 1.09714285714 |
| pounds | 0.06857142857 lb | × 0.0685714285714 |
| stone | 0.004897959184 st | × 0.00489795918367 |
| US tons | 0.00003428571429 ton | × 0.0000342857142857 |
| micrograms | 31,103,476.8 mcg | × 31,103,476.8 |
| milligrams | 31,103.4768 mg | × 31,103.4768 |
| centigrams | 3,110.34768 cg | × 3,110.34768 |
| grams | 31.1034768 g | × 31.1034768 |
| kilograms | 0.0311034768 kg | × 0.0311034768 |
| slugs | 0.002131265155 slug | × 0.00213126515462 |
| tonnes | 0.0000311034768 t | × 0.0000311034768 |
| carats | 155.517384 ct | × 155.517384 |
| troy ounces (as entered) | 1 ozt | — |
| grains | 480 gr | × 480 |
| long tons | 0.0000306122449 LT | × 0.000030612244898 |
Factors are entered by hand from NIST Handbook 44 rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert troy ounces to carats? The converter and the working
- 1.Take the measurement in troy ounces.
- 2.Multiply by 155.51738 — that is how many carats fit in one troy ounce.
- 3.To go back the other way, divide by 155.51738, or multiply by 0.0064301493.
Worked example: 25 troy ounces to carats
- Formula
- ozt × 155.51738 = ct
- Arithmetic
- 25 × 155.51738 = 3,887.93 ct
- Answer
- 25 ozt = 3,887.93 ct
The factor is rounded for display; the figure above is computed from the full value.
Troy ounces to carats conversion table
| Troy ounces | Carats |
|---|---|
| 1 ozt | 155.52 ct |
| 2 ozt | 311.03 ct |
| 3 ozt | 466.55 ct |
| 4 ozt | 622.07 ct |
| 5 ozt | 777.59 ct |
| 6 ozt | 933.1 ct |
| 7 ozt | 1,088.62 ct |
| 8 ozt | 1,244.14 ct |
| 9 ozt | 1,399.66 ct |
| 10 ozt | 1,555.17 ct |
| 12 ozt | 1,866.21 ct |
| 15 ozt | 2,332.76 ct |
| 20 ozt | 3,110.35 ct |
| 25 ozt | 3,887.93 ct |
| 50 ozt | 7,775.87 ct |
| 100 ozt | 15,551.74 ct |
| 200 ozt | 31,103.48 ct |
| 300 ozt | 46,655.22 ct |
| 500 ozt | 77,758.69 ct |
| 1000 ozt | 155,517.38 ct |
| 2000 ozt | 311,034.77 ct |
| 5000 ozt | 777,586.92 ct |
| 10000 ozt | 1,555,173.84 ct |
What is a troy ounce?
Exactly 31.1034768 grams, and the only ounce bullion is ever quoted in. It is about 10% heavier than the ounce on a kitchen scale, so a "pound" of gold — twelve troy ounces — is lighter than a pound of anything else.
What is a carat?
Exactly 200 milligrams, fixed by international agreement in 1907 after centuries of local carats. It weighs a gemstone; the karat that grades gold is a different word for a different thing — purity in twenty-fourths.
How many carats are in a troy ounce?
One troy ounce is 155.51738 carats. Going the other way, one carat is 0.0064301493 troy ounces. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every weight unit here
The whole group — 15 units with their symbols and the size of each one in kilograms — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to a troy ounce.
Cite this page
- APA
- Rule Calculator. (2026). Convert Troy ounces to carats. Rule Calculator. https://rulecalculators.com/convert/troy-ounce-to-carat
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- Chicago
- Rule Calculator. "Convert Troy ounces to carats." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/troy-ounce-to-carat.
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Questions people actually ask
- How many carats are in a troy ounce?
- 155.51738. Exactly 200 milligrams, fixed by international agreement in 1907 after centuries of local carats. It weighs a gemstone; the karat that grades gold is a different word for a different thing — purity in twenty-fourths.
- How do I convert carats back to troy ounces?
- Divide by 155.51738, or multiply by 0.0064301493 — they are the same operation.
Other weight conversions
Carats to troy ounces — the same conversion the other way.