Pounds to Ounces (lb to oz)
1 pound equals 16 ounces exactly.
How to convert pounds to ounces
To convert pounds to ounces, multiply the number of pounds by 16. This factor is exact. To go the other way, multiply ounces by 0.0625.
ounces = pounds × 16
Example: 10 pounds = 160 ounces.
About these units
Pound (lb)
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)
Ounce (oz)
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)
Related conversions
- Ounces to pounds (reverse)
- Pounds to kilograms
- Pounds to grams
- Pounds to metric tons
- Pounds to milligrams
- Pounds to micrograms
- Pounds to carats
- Pounds to stone
- Pounds to short tons
- Pounds to long tons
- Pounds to troy ounces
- Pounds to daltons
- Pounds to Earth masses
- Kilograms to ounces
- Grams to ounces
- Metric tons to ounces
- Milligrams to ounces
- Micrograms to ounces
- Carats to ounces
- Stone to ounces
- Short tons to ounces
- Long tons to ounces
- Troy ounces to ounces
- Daltons to ounces
- Earth masses to ounces
See all weight & mass units.