Convert Quarters to Apothecary Ounces
Convert Quarters (qr) to Apothecary Ounces (oz ap) instantly and accurately.
Conversion Formula
oz ap = qr × 408.3333333
About Quarters
A quarter (qr) in the avoirdupois system equals 28 pounds or one quarter of a hundredweight - approximately 12.70 kg. Historically, quarters were used in British trade for measuring grain, wool, and other bulk commodities. The British quarter of grain (28 lb) was the standard purchase quantity at markets and mills throughout medieval and early modern England. In the US, the term 'quarter' sometimes refers to a quarter of a short hundredweight (25 lb) rather than the British 28 lb.
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 Although the apothecary system has been replaced by SI units in modern medicine, the apothecary ounce still appears in historical pharmacopeias, traditional herbal medicine texts, and some compounding pharmacy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
| Quarters (qr) | Apothecary Ounces (oz ap) |
|---|---|
| 1 qr | 408.333 oz ap |
| 2 qr | 816.667 oz ap |
| 5 qr | 2041.67 oz ap |
| 10 qr | 4083.33 oz ap |
| 25 qr | 10208.3 oz ap |
| 50 qr | 20416.7 oz ap |
| 100 qr | 40833.3 oz ap |