Convert Pound (lb) to Pennyweight (pwt) instantly.
About these units
Pound (lb)
The pound is a traditional unit of mass widely used in the United States and, to a lesser extent, in the United Kingdom. Defined as exactly 0.45359237 kilograms, the pound evolved from medieval English systems that themselves descended from Roman and Carolingian traditions. The pound is central to commerce, engineering, food measurement, and body weight scales in the US. Its widespread cultural presence makes it deeply familiar even in contexts where metric units dominate. Because the pound is part of a non-decimal system, subdivisions such as ounces (1/16 pound) introduce complexity, yet this structure persists due to tradition and embedded industrial standards. In engineering, the pound often appears alongside pound-force, making careful distinction between mass and force essential.
Pennyweight (pwt)
The pennyweight, equal to 1/20 of a troy ounce or 1.55517384 grams, is a unit used primarily in the precious metals and jewelry industries. Its origins lie in medieval English coinage, when the weight of silver pennies provided a practical standard for small masses. Jewelers continue to use the pennyweight because many traditional pricing structures and metalworking conventions are built around troy-based subdivisions. For gold, silver, and dental alloys, the pennyweight remains easier to work with than grams due to long-established norms. Even though the metric system is now dominant scientifically, the pennyweight persists because industries tied to history—especially those involving money and precious goods—tend to maintain deeply rooted practices.