Troy Pounds to Pounds (lb t to lb)

1 troy pound equals 0.8228571429 pounds (rounded).

1 troy pound = 0.8228571429 pounds

How to convert troy pounds to pounds

To convert troy pounds to pounds, multiply the number of troy pounds by 0.8228571429. The factor is rounded to 10 significant digits. To go the other way, multiply pounds by 1.215277778 (rounded).

pounds = troy pounds × 0.8228571429

Example: 10 troy pounds = 8.228571429 pounds.

About these units

Troy Pound (lb t)

Troy & apothecaries'Historical unit (no longer in standard use)

12 troy ounces (373.24 g). Formerly used for precious metals in the UK and US.

Twelve troy ounces made one troy pound, a heavier-feeling number than it sounds because the troy ounce itself is larger than the avoirdupois ounce. The pound holds 5,760 grains, which comes to about 373.24 grams, noticeably lighter than the 453.6 gram avoirdupois pound. The name probably points to the fairs of Troyes in France, although that origin is not certain.

Goldsmiths, silversmiths and mints used it for precious metals, and it was kept in the American system even though people rarely ask for it there today. In Britain the troy pound lost its official status in the nineteenth century, while the troy ounce stayed legal for precious metals.

Everyday use survives only through the ounce. Bullion prices are still quoted per troy ounce, which is one twelfth of this unit, so a troy pound corresponds to twelve of those bullion ounces.

1 troy pound = 0.3732417216 kilograms (exactly).

Sources: Wikipedia: Troy weight; Wikipedia: Pennyweight; NIST SP 811, Appendix B.8

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)

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