Convert Attogram (ag) to Stone (US) (st (US)) instantly.
About these units
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.
Stone (US) (st (US))
The US stone was an informal and nonstandardized unit occasionally used in the 19th century, with no single agreed-upon value. Unlike the British stone (14 pounds), the US stone varied regionally and by trade context, typically ranging from 12 to 16 pounds, depending on the commodity and location. Farmers, butchers, and merchants sometimes used stones to weigh produce, meat, or livestock, but the lack of uniform regulation prevented it from becoming an official or widely adopted unit. Today, the US stone is entirely obsolete, but references to it appear in historical American trade documents, agricultural records, and pre-standardization weight systems. It serves as a reminder of the diversity of early American measurements before the widespread adoption of the avoirdupois pound.