What is ounce?
An ounce is a unit of mass in imperial and US customary systems equal to approximately 28.35 grams. It is frequently used in cooking, food portioning, and the measurement of precious metals.
Real-world uses
Ounces are used in the US and UK for food packaging, postal weights, and cooking recipes. Precious metals are weighed in troy ounces (slightly heavier than avoirdupois ounces) on commodity exchanges worldwide.
History
The word "ounce" comes from the Latin "uncia," meaning one-twelfth (of a Roman pound). The avoirdupois ounce became standard in English trade by the 14th century, defined as 1/16 of an avoirdupois pound.
Common mistakes
Confusing avoirdupois ounces (28.35 g, used for general weight) with troy ounces (31.10 g, used for precious metals) or fluid ounces (a volume measure). These are three distinct units sharing the name "ounce."
What is milligram?
A milligram is a metric unit of mass equal to one thousandth of a gram. It is commonly used in pharmaceutical dosing, nutritional content labelling, and laboratory chemistry.
Real-world uses
Milligrams are the standard unit for pharmaceutical dosages (e.g., 500 mg ibuprofen), nutritional supplement quantities, and blood test results such as cholesterol levels (mg/dL). Environmental scientists measure pollutant concentrations in mg/L.
History
The milligram was established with the metric system's prefix conventions in the 1790s. Its importance grew dramatically with modern pharmacology, where precise small-mass measurements became critical for drug safety and efficacy.
Common mistakes
Confusing milligrams with micrograms—a factor-of-1000 error that can be dangerous in medication dosing. The abbreviation "mcg" is sometimes used for micrograms to avoid confusion with "mg."
When is this conversion used?
Converting between ounce and milligram is common when working across metric and imperial systems, such as international trade, travel between countries with different measurement standards, or following instructions from a different region. Cooking recipes and food packaging often switch between grams and ounces, especially when adapting recipes from different culinary traditions.
Worked examples
1 ounce = 28,349.523125 milligram
1 milligram = 0.000001 kilogram
How to convert ounce to milligram
To convert ounce to milligram, multiply the value by 28,349.523125.
To convert milligram back to ounce, multiply by 0.00003527.
Measurement standards
The kilogram is defined by fixing the Planck constant to exactly 6.62607015 × 10⁻³⁴ joule-seconds, as established at the 26th General Conference on Weights and Measures in 2018. This ended the last SI definition based on a physical artefact.
Did you know?
The International Prototype of the Kilogram, a platinum-iridium cylinder stored near Paris since 1889, was found to have drifted by about 50 micrograms relative to its copies over a century — roughly the mass of a fingerprint.
Quick reference: ounce to milligram
| ounce | milligram |
|---|---|
| 0.1 | 2,834.9523125 |
| 0.5 | 14,174.7615625 |
| 1 | 28,349.523125 |
| 2 | 56,699.04625 |
| 5 | 141,747.615625 |
| 10 | 283,495.23125 |
| 25 | 708,738.078125 |
| 50 | 1,417,476.15625 |
| 100 | 2,834,952.3125 |
| 250 | 7,087,380.78125 |
| 500 | 14,174,761.5625 |
| 1,000 | 28,349,523.125 |
Common values
| ounce | milligram | |
|---|---|---|
| A paperclip | 35.27396195 ounce | 1,000,000 milligram |
| A smartphone | 6,172.94334118 ounce | 175,000,000 milligram |
| A bag of sugar | 35.27396195 ounce | 1,000,000 milligram |
| Average adult human | 2,469.17733647 ounce | 70,000,000 milligram |
| A small car | 42,328.7543395 ounce | 1.200000e+09 milligram |