Ounce to Milligram Converter
Quick answer
To convert Ounces to Milligrams, multiply by 28,349.523125 (or divide by 3.527396e-5). Therefore, 1 Ounce (oz) equals 28,349.523125 Milligrams (mg).
Formula: mg = oz × 28,349.523125. Worked example: 10 oz = 283,495.23125 mg.
Convert Ounce (oz) to Milligram (mg) online with our free unit converter. In mass, 1 oz = 28,349.523125 mg. Explore step-by-step conversion steps, mathematical formulas, and quick conversion reference tables below.
Worked example: converting Ounce to Milligram
- Step 1 — start with the formula. mg = oz × 28,349.523125
- Step 2 — substitute your figure. 10 oz × 28,349.523125
- Step 3 — read the result. 10 oz = 283,495.23125 mg
- Step 4 — check it in reverse. oz = mg × 0.000035274 returns Invalid oz, which matches the figure you started with.
Mass Converter
26 units available
1 oz = 28,349.523125 mg
Formula:
mg = oz × 28,349.523125With your value: 1 oz = 28,349.523125 mg
How big is that?
Everyday references on a logarithmic scale, all expressed in ounce so you can sanity-check the result.
Other Ounce to Milligram conversions
Ounce to Milligram Conversion Table
| Ounce (oz) | Milligram (mg) |
|---|---|
| 0.5 | 14,174.761563 |
| 1 | 28,349.523125 |
| 2 | 56,699.04625 |
| 5 | 141,747.615625 |
| 10 | 283,495.23125 |
| 15 | 425,242.846875 |
| 20 | 566,990.4625 |
| 25 | 708,738.078125 |
| 50 | 1,417,476.15625 |
| 100 | 2,834,952.3125 |
| 250 | 7,087,380.78125 |
| 500 | 14,174,761.5625 |
| 1000 | 28,349,523.125 |
Milligram to Ounce Conversion Table
| Milligram (mg) | Ounce (oz) |
|---|---|
| 0.5 | 1.763698e-5 |
| 1 | 3.527396e-5 |
| 2 | 7.054792e-5 |
| 5 | 0.000176 |
| 10 | 0.000353 |
| 15 | 0.000529 |
| 20 | 0.000705 |
| 25 | 0.000882 |
| 50 | 0.001764 |
| 100 | 0.003527 |
| 250 | 0.008818 |
| 500 | 0.017637 |
| 1000 | 0.035274 |
Where these values come from
Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.
Ounce (oz)
Mass
1 avoirdupois ounce = 1/16 lb = 0.028 349 523 125 kg exactly.
Source: International Yard and Pound Agreement of 1959; NIST Federal Register Notice 59-5442
US, UK, Canada, Australia, New Zealand, South Africa · Reviewed 2026-07-01
Milligram (mg)
Mass
Traceable to the kilogram, defined by fixing the Planck constant at 6.626 070 15 × 10⁻³⁴ J·s. Avoirdupois masses derive from the 1959 international pound (0.453 592 37 kg exactly).
Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)
Bureau International des Poids et Mesures · Reviewed 2026-07-01
How to Convert Ounce to Milligram
To convert from Ounce (oz) to Milligram (mg), multiply the value by 28,349.523125.
Formula: mg = oz × 28,349.523125
Reverse: oz = mg × 0.000035274
Step-by-Step Example
- Start with your value in Ounce. For example: 5 oz
- Multiply by the conversion factor: 5 x 28,349.523125
- The result is: 141,747.615625 mg
Ounce and Milligram Relationship
This conversion bridges the US Customary / Imperial and Metric (SI) measurement systems, commonly required when translating scientific data, international engineering specifications, or trade standards. Since 1 Ounce equals approximately 2.835e+4 Milligrams, the Ounce represents a larger unit interval than the Milligram. Understanding the relationship between Ounce and Milligram is essential for accurate calculations in physics, engineering, commerce, and daily applications.
About Ounce
The ounce (oz) equals 1/16 of a pound or approximately 28.35 grams. It is used for food portions and small weight measurements.
Common uses of Ounce: food portions, postal mail, precious metals.
About Milligram
The milligram equals one thousandth of a gram and is the standard unit for drug dosage and nutrient quantities.
Common uses of Milligram: medication dosage, nutrition labels, laboratory work.
Frequently Asked Questions
- How many Milligrams are in 1 Ounce?
- There are exactly 28,349.523125 Milligrams in 1 Ounce. This means the conversion factor from Ounce to Milligram is 28,349.523125.
- What is the formula to convert Ounce to Milligram?
- The formula to convert Ounce to Milligram is: mg = oz × 28,349.523125. For example, to convert 10 Ounces to Milligrams, you would multiply 10 by 28,349.523125.
- What is a Ounce?
- The ounce (oz) equals 1/16 of a pound or approximately 28.35 grams. It is used for food portions and small weight measurements.
- What is a Milligram?
- The milligram equals one thousandth of a gram and is the standard unit for drug dosage and nutrient quantities.
- What are the common uses of Ounce?
- The Ounce is commonly used in food portions, postal mail, precious metals.
Related Mass Conversions
Cite this page
UnitConvertLab. (2026). Ounce to Milligram converter. UnitConvertLab. Retrieved from https://unitconvertlab.com/convert/ounce-to-milligram