A metric carat is exactly 200 milligrams.
Carats to Ounces Converter — ct to oz
Convert Carat (ct) to Ounce (oz) using the exact conversion factor (1 carat = 0.0070547924 ounce). See the formula, worked examples, conversion table, history, and common uses.
Carats to Ounces converter
Converter
Mass/Weight Converter
Convert SI mass, imperial weight, jewelry, atomic, and astronomy mass units.
Context values
Some unit families need one extra value for a physically accurate result.
An avoirdupois ounce is 1/16 pound.
Result = input x 0.0002 / 0.02834952313.
Mass uses the kilogram as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Carats to Ounces
Weight conversions between Carat and Ounce come up constantly in everyday commerce, shipping, and cooking, since US packaging is usually labeled in pounds while most of the rest of the world uses kilograms. Specifically: A metric carat is exactly 200 milligrams, and an avoirdupois ounce is 1/16 pound.
Formula
ounces = carats × 0.00705479238992
This factor comes from each unit's defined relationship to the category's base unit: 1 carat equals 0.0002 base units, and 1 ounce equals 0.028349523125 base units, so dividing one by the other gives the direct carat-to-ounce factor of 0.00705479238992.
Simple example
1 ct × 0.00705479239 = 0.0070547924 oz
1 carat = 0.0070547924 ounces.
Real-world example
50 ct × 0.00705479239 = 0.3527396195 oz
50 carats = 0.3527396195 ounces.
Conversion table
| Carat (ct) | Ounce (oz) |
|---|---|
| 1 ct | 0.0070547924 oz |
| 5 ct | 0.035273962 oz |
| 10 ct | 0.0705479239 oz |
| 25 ct | 0.1763698097 oz |
| 50 ct | 0.3527396195 oz |
| 100 ct | 0.705479239 oz |
Reverse conversion: Ounce to Carat
0.0070547924 oz × 141.7476156 = 1.000000001 ct
0.0070547924 ounces = 1.000000001 carats.
carats = ounces × 141.747615625
For a page dedicated to this direction, see Ounce to Carat.
Understanding the Carat (ct)
A metric carat is exactly 200 milligrams.
Understanding the Ounce
Ounce (oz) measures mass. The avoirdupois ounce is 1/16 of a pound: exactly 28.349523125 grams. It is classified as a US/imperial customary unit.
Where it's used: United States (cooking, postal, retail) United Kingdom (informal/retail use)
Avoirdupois ounce vs. troy ounce. The everyday ounce (avoirdupois, 28.35 g) used for cooking and shipping is a different, smaller unit than the troy ounce (31.10 g) used for precious metals like gold and silver — this page uses the everyday avoirdupois ounce.
Uses of the Ounce today
- US cooking and recipe measurement (small quantities)
- US postal and shipping weight
- Precious metals (troy ounce, a related but distinct unit)
History of the Ounce
The ounce descends from the Roman 'uncia' (a twelfth part), inherited through medieval English weight systems; the avoirdupois ounce (for general goods, as opposed to the troy ounce for precious metals) became standard for everyday trade, fixed at exactly 28.349523125 g via the pound's 1959 international standardization.
Historical origin. Ounce was not the invention of a single named person; it developed through the process described above.
Ounce — sources
- NIST — International yard and pound (1959) — Basis for the modern ounce via the standardized pound.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many ounces are in 1 carat?
1 carat equals 0.0070547924 ounces, using the exact defined conversion factor rather than an estimate.
How do I convert carat to ounce?
Multiply the carat value by 0.00705479239. The converter above does this instantly to whatever precision you set.
How do I convert ounce back to carat?
Use the reverse factor: 1 ounce equals 141.7476156 carats. You can also use the swap control in the converter above to flip the direction instantly.
What is a carat?
Carat (ct) is a unit of mass/weight.
What is a ounce?
Ounce (oz) measures mass. The avoirdupois ounce is 1/16 of a pound: exactly 28.349523125 grams. It is classified as a US/imperial customary unit.
Is the carat to ounce conversion exact?
Yes. The avoirdupois ounce is 1/16 of a pound: exactly 28.349523125 grams. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
What is the difference between avoirdupois ounce vs. troy ounce?
The everyday ounce (avoirdupois, 28.35 g) used for cooking and shipping is a different, smaller unit than the troy ounce (31.10 g) used for precious metals like gold and silver — this page uses the everyday avoirdupois ounce.