Convert Carats to Apothecary Ounces
Convert Carats (ct) to Apothecary Ounces (oz ap) instantly and accurately.
Conversion Formula
oz ap = ct × 0.006430149314
About Carats
A metric carat (ct or CD) is exactly 200 milligrams (0.2 g), the universal standard for weighing gemstones. Established internationally in 1907, it replaced fractionally different regional carat weights previously used in different countries. The total weight of a diamond or colored gemstone is always expressed in carats: a 1.00 ct diamond of excellent cut and color can command over $5,000. The Cullinan diamond, the largest gem-quality rough diamond ever found, weighed 3,106.75 carats.
About Apothecary Ounces
An apothecary ounce (oz ap) is identical in mass to the troy ounce - approximately 31.10 grams - and equals 8 apothecary drams or 480 grains. It was the standard ounce used by pharmacists and physicians across Europe and North America from medieval times until the 20th century. Although the apothecary system has been replaced by SI units in modern medicine, the apothecary ounce still appears in historical pharmacopeias, traditional herbal medicine texts, and some compounding pharmacy references.
Quick Reference Table
| Carats (ct) | Apothecary Ounces (oz ap) |
|---|---|
| 1 ct | 0.00643015 oz ap |
| 2 ct | 0.0128603 oz ap |
| 5 ct | 0.0321507 oz ap |
| 10 ct | 0.0643015 oz ap |
| 25 ct | 0.160754 oz ap |
| 50 ct | 0.321507 oz ap |
| 100 ct | 0.643015 oz ap |