Ounce to Milligram Conversion Calculator: Free Online Tool
Convert ounces to milligrams with our free online weight converter.
Ounce to Milligram Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Ounce).
- The converted value in Milligram will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Weight category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Ounce to Milligram
Converting Ounce to Milligram involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Ounce = 28349.5 milligramsExample Calculation:
Convert 5 ounces: 5 × 28349.5 = 141748 milligrams
Disclaimer: For Reference Only
These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.
Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.
What is a Ounce and a Milligram?
The ounce (oz) is a unit of mass used in the British imperial and United States customary systems of measurement. The most common type today is the international avoirdupois ounce, defined as exactly 1/16 of an avoirdupois pound, or approximately 28.35 grams.
The milligram is a unit of mass in the metric system equal to one-thousandth of a gram (1/1000 g) or one-millionth of a kilogram (1/1,000,000 kg). It is commonly used for measuring very small quantities.
Note: The Ounce is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Milligram belongs to the metric (SI) system.
History of the Ounce and Milligram
The term "ounce" derives from the Roman "uncia", which was one-twelfth of the Roman pound. Its value varied throughout history and regions. The avoirdupois ounce became standardized in the English-speaking world for general trade.
Like the gram, the milligram's definition is derived directly from the kilogram. Its use became prevalent with the need for precise measurements in science and medicine as the metric system was adopted globally.
Common Uses for ounces and milligrams
Explore the typical applications for both Ounce (imperial/US) and Milligram (metric) to understand their common contexts.
Common Uses for ounces
- Cooking & Recipes: Standard unit in the US for measuring food ingredients like flour, sugar, spices, and non-liquid items in recipes.
- Packaged Foods: Used for labeling the net weight of many packaged food products (e.g., cereal boxes, canned goods, snacks).
- Postal Services: Used for determining the weight and cost of letters and small parcels, especially in the US.
- Deli & Groceries: Common unit for measuring small portions of items like cheese, deli meats, and specialty foods.
- Precious Metals: Often used to measure the weight of gold, silver, and other precious metals in jewelry and bullion.
Common Uses for milligrams
- Pharmaceuticals: Measuring the dosage of medications, pills, and active ingredients in drugs.
- Scientific Research: Common unit for mass measurements in chemistry labs, biology, and physics experiments for very small quantities.
- Nutrition & Supplements: Used for labeling the content of vitamins, minerals, and other nutrients in dietary supplements.
- Precision Manufacturing: Weighing very lightweight items like microelectronic components, fine powders, or precious materials.
- Analytical Chemistry: Standard unit for quantifying trace elements and compounds in samples.
Frequently Asked Questions
Questions About Ounce (oz)
How many ounces are in a pound?
There are 16 avoirdupois ounces (oz) in 1 pound (lb).
Is an ounce the same as a fluid ounce?
No. The ounce (oz) measures mass/weight, while the fluid ounce (fl oz) measures volume.
Where is the ounce commonly used?
It is primarily used in the United States for everyday measurements, and to some extent in the UK and Canada, though metric units are more prevalent globally.
About Milligram (mg)
How many milligrams are in a gram?
There are 1,000 milligrams (mg) in 1 gram (g).
Is the milligram used in everyday life?
Its most common everyday use is in medication dosages and supplement information. It's less common for general weighing compared to grams or kilograms.
What does 'milli' mean in milligram?
The prefix 'milli' denotes one-thousandth (1/1000).
Conversion Table: Ounce to Milligram
| Ounce (oz) | Milligram (mg) |
|---|---|
| 1 | 28,349.523 |
| 5 | 141,747.616 |
| 10 | 283,495.231 |
| 25 | 708,738.078 |
| 50 | 1,417,476.155 |
| 100 | 2,834,952.31 |
| 500 | 14,174,761.55 |
| 1,000 | 28,349,523.1 |
All Weight Conversions
Other Units from Weight
- Kilogram (kg)
- Gram (g)
- Pound (lb)
- Stone (st)
- Ton (metric) (t)
- Ton (US) (ton)
- Ton (UK) (long ton)
- Microgram (µg)
- Carat (ct)
- Slug (sl)
- Troy Ounce (oz t)
- Pennyweight (dwt)
- Grain (gr)
- Dram (dr)
- Quintal (q)
- Atomic Mass Unit (u)
- Pavan (India) (pavan)
- Kati (India) (kati)
- Masha (India) (masha)
- Dina (India) (dina)
- Pras (India) (pras)
- Lota (India) (lota)