Convert Apothecary Ounces to Milligrams
Convert Apothecary Ounces (oz ap) to Milligrams (mg) instantly and accurately.
Conversion Formula
mg = oz ap × 31103.4768
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 Although the apothecary system has been replaced by SI units in modern medicine, the apothecary ounce still appears in historical pharmacopeias, traditional herbal medicine texts, and some compounding pharmacy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.
About Milligrams
A milligram (mg) is one thousandth of a gram (10⁻³ g). It is the primary unit for pharmaceutical dosing: aspirin tablets are typically 500 mg, ibuprofen 200-400 mg, and melatonin supplements 0.5-10 mg. Precious metal assay results and alloy compositions are specified in milligrams per kilogram (mg/kg = ppm). Nutritional labels worldwide list mineral content in milligrams - the recommended daily intake of iron is 8-18 mg, calcium 1000 mg, and sodium under 2300 mg. A grain of rice weighs about 25-30 mg, and a medium eyelash approximately 0.1 mg.
Quick Reference Table
| Apothecary Ounces (oz ap) | Milligrams (mg) |
|---|---|
| 1 oz ap | 31103.5 mg |
| 2 oz ap | 62207 mg |
| 5 oz ap | 155517 mg |
| 10 oz ap | 311035 mg |
| 25 oz ap | 777587 mg |
| 50 oz ap | 1555170 mg |
| 100 oz ap | 3110350 mg |