Ounce to Milligram Converter
Type a value — the answer appears instantly. 1 oz = 28,349.5 mg.
Reviewed by the OmniCalc teamMethod verified 2026-07-01
28,349.5 milligrams
= 0.0283495 kg= 0.0625 lb
equals 28,349.5 milligramsFormula: mg = oz × 28349.523
Ounce to Milligram formula
mg = oz × 28349.523
Convert 5 ounces to milligrams
- Start with 5 ounces.
- Multiply by the conversion factor: 5 × 28,349.5 = 141,748.
- So 5 oz = 141,748 mg.
Ounce to Milligram conversion table
| Ounces (oz) | Milligrams (mg) |
|---|---|
| 0.01 oz | 283.495 mg |
| 0.1 oz | 2,834.95 mg |
| 0.25 oz | 7,087.38 mg |
| 0.5 oz | 14,174.8 mg |
| 1 oz | 28,349.5 mg |
| 2 oz | 56,699 mg |
| 3 oz | 85,048.6 mg |
| 4 oz | 113,398 mg |
| 5 oz | 141,748 mg |
| 6 oz | 170,097 mg |
| 7 oz | 198,447 mg |
| 8 oz | 226,796 mg |
| 9 oz | 255,146 mg |
| 10 oz | 283,495 mg |
| 15 oz | 425,243 mg |
| 20 oz | 566,990 mg |
| 25 oz | 708,738 mg |
| 30 oz | 850,486 mg |
| 40 oz | 1,133,980 mg |
| 50 oz | 1,417,480 mg |
| 75 oz | 2,126,210 mg |
| 100 oz | 2,834,950 mg |
| 250 oz | 7,087,380 mg |
| 500 oz | 14,174,800 mg |
| 1,000 oz | 28,349,500 mg |
| 5,000 oz | 141,748,000 mg |
| 10,000 oz | 283,495,000 mg |
Unit definitions
What is a ounce?
The avoirdupois ounce is one sixteenth of a pound, about 28.35 grams. It is common in the United States for food portions, packaged goods, and postal weights. It should not be confused with the troy ounce used for precious metals.
What is a milligram?
The milligram is one millionth of a kilogram, or one thousandth of a gram. It is the standard unit for dosing medication, vitamins, and nutritional supplements, and for weighing very small quantities in laboratories. A grain of table salt weighs roughly one milligram.
Frequently asked questions
How many milligrams are in one ounce?
One ounce equals 28,349.5 milligrams (1 oz = 28,349.5 mg).
How do I convert ounces to milligrams?
Multiply the value in ounces by 28,349.5. For example, 10 oz × 28,349.5 = 283,495 mg.
Which is bigger — a ounce or a milligram?
A ounce is bigger: one ounce contains 28,349.5 milligrams.
Is this ounce to milligram converter free?
Yes — the converter is free, works offline once loaded, and computes instantly in your browser without sending your numbers to a server.
Conversion factors follow international definitions (SI / NIST). Last verified 2026-07-01.