Ounces to Micrograms (oz to µg)

1 ounce equals 28,349,523.13 micrograms (rounded).

1 ounce = 28,349,523.13 micrograms

How to convert ounces to micrograms

To convert ounces to micrograms, multiply the number of ounces by 28,349,523.13. The factor is rounded to 10 significant digits. To go the other way, multiply micrograms by 3.527396195×10⁻⁸ (rounded).

micrograms = ounces × 28,349,523.13

Example: 10 ounces = 283,495,231.3 micrograms.

About these units

Ounce (oz)

US & ImperialCurrent unit

One sixteenth of a pound, exactly 28.349523125 g. Used for food, mail and consumer goods in the US and UK.

A twelfth part is what ounce originally meant. It comes from the Roman uncia, one twelfth of the Roman pound, a word that also gave English the inch. The abbreviation oz does not come from English at all but from the Italian onza or oncia. Over the centuries many regions and trades used different ounces: the English Tower ounce of 29.16 g was abolished by Henry VIII in 1527, and the Dutch ons was redefined as exactly 100 g in 1820.

The avoirdupois ounce used for everyday goods is one sixteenth of a pound, exactly 28.349523125 g or 437.5 grains, the standard in the US and under the UK imperial system. It is not the same as the troy ounce for precious metals, and neither is the fluid ounce, which measures volume. Ounces still describe portions such as steaks and burgers, and they show up in unexpected places: fabric is graded by weight per area, so a 16 oz denim is a heavy cloth, and the copper on a circuit board is specified in ounces, where 1 oz is roughly 34.7 micrometres thick.

1 ounce = 0.02834952313 kilograms (approximately).

Sources: Wikipedia: Ounce; NIST Guide to the SI, Appendix B.8 (mass conversions)

Microgram (µg)

Metric (SI)Current unit

One millionth of a gram. Used for very small doses such as vitamin B12 and folic acid; often written mcg on labels.

Tiny doses forced the microgram into everyday use. It is one millionth of a gram, written with the SI prefix micro and the Greek letter mu, but that letter caused trouble: handwritten or badly printed, mu can look like a lowercase m, which would turn micro into milli and make a dose a thousand times too large. For that reason the US Institute for Safe Medication Practices and the FDA recommend writing mcg in medical communication, while UK prescribing guidance says microgram should be written out in full rather than abbreviated.

You meet the unit mostly on nutrition labels and in medicine, where amounts such as folic acid and vitamin B12 are given in micrograms. It also matters in laboratories. According to NIST, the old kilogram prototype gave relative uncertainties of a few parts in ten thousand at the milligram level, and fields such as pharmaceuticals and materials science increasingly need dependable accuracy down at the microgram, which was one argument for redefining the kilogram with a fundamental constant. In text where mu is unavailable, people type u or the micro sign instead.

1 microgram = 1×10⁻⁹ kilograms (exactly).

Sources: Wikipedia: Microgram; NIST: Kilogram introduction (SI redefinition)

Related conversions

See all weight & mass units.