Troy Pound (lb t)
The troy pound is a unit of mass in the troy weight system, equal to 12 troy ounces or approximately 373.24 grams. It is lighter than the common avoirdupois pound (453.59 grams) because it contains only 12 ounces instead of 16. The troy pound is largely obsolete today, having been superseded by the troy ounce for precious metals and by the avoirdupois pound or kilogram for everything else.
Definition
One troy pound equals exactly 12 troy ounces, 240 pennyweights, 5,760 grains, or approximately 373.2417216 grams. A troy pound is lighter than an avoirdupois pound: 373.24 g vs. 453.59 g, a difference of about 80 grams or 17.6%.
History
The troy pound, like the troy ounce, takes its name from the medieval French city of Troyes. It was the standard pound used in England for gold and silver from the Middle Ages until the 19th century. The troy pound was legally abolished in the United Kingdom in 1878 by the Weights and Measures Act, which retained only the troy ounce for precious metals. In the US, the troy pound was defined as 5,760 grains (373.2417216 grams) by the Mendenhall Order of 1893. It remains technically legal but is virtually never used.
Common Uses
The troy pound has essentially no modern applications. Precious metals are traded in troy ounces, not troy pounds. The unit survives only in historical records, legal definitions, and educational materials about weight systems. Understanding the troy pound is necessary for interpreting pre-19th-century British gold and silver records.
Did You Know? Facts About Troy Pound
- A troy pound (373 g) is about 80 grams lighter than an avoirdupois pound (454 g) - the rare case where "a pound" of gold weighs less than "a pound" of feathers.
- The troy pound was legally abolished in the UK in 1878, but the troy ounce survived and is still the global standard for gold pricing.
- 12 troy ounces make one troy pound, while 16 avoirdupois ounces make one avoirdupois pound.
- Confusingly, a troy ounce (31.1 g) is heavier than an avoirdupois ounce (28.35 g), even though a troy pound is lighter than an avoirdupois pound.
- The troy pound of 5,760 grains was the basis for the original British pound sterling - one pound of silver coins literally weighed one troy pound.