Convert Femtogram (fg) to Stone (US) (st (US)) instantly.
About these units
Femtogram (fg)
A femtogram is 10⁻¹⁵ grams, an extraordinarily small unit used primarily in molecular biology, analytical chemistry, and particle science. At this scale, masses correspond to small clusters of molecules, fragments of genetic material, or trace contaminants in environmental samples. In genomics, for example, the femtogram level may represent the mass of DNA extracted from just a few cells, pushing the limits of current sequencing technologies. Advanced mass spectrometers and nanoscale resonators can detect femtogram-level differences, revealing chemical changes invisible at larger scales. The femtogram symbolizes the reach of modern science into realms once thought beyond measurement. As techniques continue to improve, femtogram-level precision will become increasingly common in nanotechnology and biophysics.
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.