How to convert ounces to milligrams
Ounces and Milligrams both measure weight, so converting is a single multiplication. One oz equals 28,349.5 mg, so you multiply your ounces value by 28,349.5.
Formula: milligrams = ounces × 28,349.5. For example, 10 oz = 283,495 mg.
Ounces to Milligrams conversion table
| Ounces (oz) | Milligrams (mg) |
|---|---|
| 1 | 28,349.5 |
| 2 | 56,699 |
| 5 | 141,747.5 |
| 10 | 283,495 |
| 25 | 708,737.5 |
| 50 | 1,417,475 |
| 100 | 2,834,950 |
| 1,000 | 28,349,500 |
Ounces and Milligrams explained
Ounces (oz): An imperial unit equal to about 28.35 g, used for food and postage in the US.
Milligrams (mg): One-thousandth of a gram, used for medication doses and nutrition labels.
When you'd convert ounces to milligrams
You'll convert ounces to milligrams whenever a measurement is given in one unit but you need it in the other — comparing ounces and milligrams figures across regions, following a recipe or spec, or double-checking a number. Because 1 oz is exactly 28,349.5 mg, the result is precise every time.
Frequently asked questions
How many milligrams are in a ounce?
One oz equals 28,349.5 mg. Multiply your ounces figure by 28,349.5 to get milligrams.
What is the formula to convert ounces to milligrams?
milligrams = ounces × 28,349.5. The factor 28,349.5 is exact.
What is 2 ounces in milligrams?
2 oz = 56,699 mg. You can enter any value in the converter above to get an instant result.
Is this Ounces to Milligrams converter accurate?
Yes. It uses the standard conversion factor (1 oz = 28,349.5 mg) defined by BIPM — SI Brochure (definition of the kilogram), so results are exact to several decimal places.