Ounces (oz) to Milligrams (mg) Converter
Enter a value to instantly convert between weight units.
1 Ounce = 28349.5231 Milligram
Key Formulas
Kilogram → Pound
lb = kg × 2.20462Pound → Kilogram
kg = lb × 0.453592Gram → Ounce
oz = g × 0.035274Ounce → Gram
g = oz × 28.3495Formula
mg = oz × 28349.5One ounce is 28,349.5 milligrams — heavy enough that even a modest number of ounces translates to large milligram amounts. US food manufacturers, pharmaceutical companies, and chemical processors regularly convert between ounces and milligrams when working with US-customary ingredient lists and metric-based production records.
Source: NIST SP 811, Table B.8
Frequently Asked Questions
Real-World Examples
A US recipe using 1 oz of baking powder converts to 28,350 mg for the nutritional database.
1 oz = 28349.5 mg
A food label showing 8 oz of cereal per serving reports 226,796 mg for the ingredient list.
8 oz = 226796 mg
A pharmacist measuring 0.25 oz of a compound needs 7087 mg for the prescription.
0.25 oz = 7087.4 mg
A US manufacturer using 16 oz (1 lb) of an ingredient records 453,592 mg for the batch record.
16 oz = 453592 mg