How To Convert Carats to Ounces
Formula: ounces = carats × 0.00705479238992
Example: Convert 12 carats to ounces.
12 × 0.00705479238992 = 0.084657508679 ounces.
To convert manually, start with the fact that 1 carat equals 0.2 grams.
Then use that 1 ounce equals 28.349523125 grams.
So you are really turning carats into grams, then grams into ounces.
Quick Answer
1 Carat = 0.00705479238992 Ounces
- 5 carats = 0.0352739619496 ounces
- 10 carats = 0.0705479238992 ounces
- 100 carats = 0.705479238992 ounces
Conversion Formula
Recommended standards used: 1 carat = 0.2 gram (international metric carat) 1 ounce = 28.349523125 grams (international avoirdupois ounce) ounces = carats × (0.2 / 28.349523125) ounces = carats × 0.00705479238992
This means every carat is a little over seven thousandths of an ounce. Because both the carat and the (avoirdupois) ounce are defined from grams, the conversion is stable and repeatable.
- Take your value in carats.
- Multiply by 0.00705479238992.
- The result is the weight in ounces.
Carat
A carat is a unit of mass used for gemstones and pearls. It is defined exactly as 200 milligrams (0.2 grams), with the symbol ct.
The metric carat was standardized in the early 1900s to stop confusion from older regional carats. It is now the global standard for diamond and gemstone trade.
- Diamond and gemstone weight in jewelry stores
- Gem lab reports and grading certificates
- Comparing stone sizes across brands and countries
- Pricing gemstones by weight (price per carat)
- Weighing pearls and small precious stones
Ounce
An ounce is a unit of mass commonly used in the United States and a few other places. In this converter, it means the avoirdupois ounce, defined exactly as 28.349523125 grams, with the symbol oz.
The ounce has roots in older Roman and European weight systems. The modern international avoirdupois ounce is tied to the pound, which is fixed by definition.
- Food weights and nutrition labels
- Shipping and package weights
- Everyday weighing on kitchen or postal scales
- Small product weights in US retail
- DIY and hobby measurements where grams are not used
Is this Conversion of Carats To Ounces Accurate?
Yes. This conversion is based on exact, defined standards. The metric carat is defined as exactly 0.2 grams, and the international avoirdupois ounce is defined as exactly 28.349523125 grams. Because both units are anchored to fixed gram values, the result is consistent for study, trade, and general use. For details on our references and standards, visit our accuracy standards page.
Real Life Examples
Carats are common in jewelry, while ounces are common on many scales. Here are realistic examples that show why this conversion helps.
- Diamond parcel for a jeweler: A parcel weighs 50 carats. That is 50 × 0.00705479238992 = 0.352739619496 ounces, useful if your scale reads in oz.
- Small lab sample: A gemstone sample is 2.5 carats. That equals 0.0176369809748 ounces, helpful when documenting weight in US units.
- Inventory batch: A shop has 200 carats of mixed stones. That converts to 1.41095847798 ounces for shipping paperwork.
- Single stone listing: A ring has a 1.2 carat center stone. That equals 0.0084657508679 ounces for customers who think in ounces.
- Buying by total weight: You buy 25 carats of small sapphires. That is 0.176369809748 ounces, useful for comparing against other lots sold by ounce.
- Repair shop intake: A bag of loose stones is 12 carats. That is 0.084657508679 ounces, quick to log if your intake scale displays oz.
- Wholesale lot: A wholesaler offers 500 carats. That equals 3.52739619496 ounces, helpful for packing and insurance weight.
Quick Tips
- Remember the anchor: 1 carat = 0.2 g.
- To get ounces fast, multiply carats by 0.0070548 (good quick estimate).
- For a reverse check, 1 ounce ≈ 141.7476 carats.
- If you have grams already, divide grams by 28.349523125 to get ounces.
- Keep enough decimals for gemstones, small weights can change price.
- Make sure your “ounce” is avoirdupois (oz), not troy ounce (ozt).