Pounds to Roman Ounces (lb to uncia)

1 pound equals 16.55446606 Roman ounces (rounded).

1 pound = 16.55446606 Roman ounces

How to convert pounds to Roman ounces

To convert pounds to Roman ounces, multiply the number of pounds by 16.55446606. The factor is rounded to 10 significant digits. To go the other way, multiply Roman ounces by 0.06040665984 (rounded).

Roman ounces = pounds × 16.55446606

Example: 10 pounds = 165.5446606 Roman ounces.

Approximate value. Standards for the Roman ounce (uncia) varied by place and period, so this converter uses the most commonly cited value. Treat results as estimates, not exact figures.

About these units

Pound (lb)

US & ImperialCurrent unit

Exactly 0.45359237 kg, divided into 16 ounces. The standard unit of weight in the US and common in the UK.

Why is pound abbreviated lb? The answer is Roman. The English word comes from the Latin libra pondo, roughly the weight measured in libra, and the symbol keeps the first word. The Roman libra was divided into 12 unciae. The avoirdupois pound of 16 ounces came into general use around 1300 and was initially equal to 6,992 troy grains; under Elizabeth I it was redefined as 7,000 grains. The UK's Weights and Measures Act 1878 set the imperial standard pound as a platinum cylinder, and the troy pound was abolished for trade the following year.

Today the pound is defined from the kilogram. The International Yard and Pound Agreement of 1959 fixed it at exactly 0.45359237 kg, and the UK's Weights and Measures Act 1963 wrote the same figure into law. Pounds remain the everyday unit for body weight, groceries and shipping in the United States and are widely used in the UK. The word also survives in odd places: a six-pounder cannon was named for the weight of its shot, not its own.

1 pound = 0.45359237 kilograms (exactly).

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

Roman Ounce (uncia) (uncia)

Ancient RomanHistorical unit (no longer in standard use)Approximate value

One twelfth of a Roman pound, about 27.4 g. The origin of the word 'ounce'.

Literally meaning a twelfth, uncia was the Roman name for one part in twelve, applied to weight, length and more. As a weight it was a twelfth of a libra. The same word, used for a twelfth of a foot, produced the English inch, so inch and ounce are cousins that split from a single Latin source.

With the libra put at 328.9 g, the uncia comes to about 27.4 g, which is the figure used here. That is a little under the modern avoirdupois ounce of 28.35 g and well below the troy ounce of about 31.1 g. Because the libra itself is estimated anywhere from 322 to 329 g, an uncia could be anywhere from about 26.8 to 27.4 g.

The unit outlived Rome. It continued as the Byzantine ounce, known in Greek as oungia, and in time spread into medieval trade systems across Europe. Many regional ounces developed, such as the Tower ounce and the Dutch ons, which was fixed at 100 g in 1820.

1 Roman ounce (uncia) = 0.0274 kilograms (approximately).

Sources: Wikipedia: Uncia (unit); Wikipedia: Ounce; Wikipedia: Roman pound

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