Troy pound
Mass · Also called: troy ounce, pennyweight
That is
373.2 g
1 troy pound (troy pound)
The other way round: 1 kg is 2.6792 troy pounds.
- Period: medieval to 6 January 1879
- Region: England
- Goods: coin, bullion, apothecaries
Values
| Value | That is | Period | Used for |
|---|---|---|---|
| troy pound | 373.2 g | medieval to 6 January 1879 | coin, bullion, apothecaries · England |
| troy ounce | 31.1 g | medieval to today | gold, silver, platinum · worldwide |
| pennyweight | 1.555 g | medieval to the 20th century | coinage · England |
What the unit was used for
Troy weight is the system of the mint, the goldsmith and the apothecary, and it takes its name from the fair at Troyes in Champagne.
The troy pound of 5760 grains is lighter than the avoirdupois pound of 7000, while the troy ounce of 480 grains is heavier than the avoirdupois ounce of 437.5.
The subdivisions record the origin in coinage: 20 pennyweight to the ounce and 24 grains to the pennyweight, the weight of an English silver penny.
The troy pound was one of the two artefact standards destroyed in the Parliament fire of 1834 and was abolished for trade on 6 January 1879, although the troy ounce was kept.
That ounce is now the only imperial unit the UK still permits as a sole legal indication in trade, for precious metals, which is why gold and silver are quoted per troy ounce.
In the system
1 troy pound = 12 troy ounces = 5760 grains; 1 troy ounce = 20 pennyweight = 480 grains