Convert Pennyweight (pwt) to Attogram (ag) instantly.
About these units
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.
Attogram (ag)
An attogram is 10⁻¹⁸ grams, an incredibly small mass used only in advanced scientific settings. At this scale, we are dealing with masses comparable to large molecules, viruses, or clusters of atoms. Modern techniques such as atomic force microscopy, mass spectrometry, and nanoscale resonators allow detection of attogram-level changes. Researchers studying chemical reactions, nanotechnology, and molecular biology may use attograms when describing ultra-fine mass differences. The attogram is an example of scientific progress: a unit unnecessary in the past, but now essential for understanding the smallest measurable interactions in nature.