Convert Stone (st) to Stone (US) (st (US)) instantly.
About these units
Stone (st)
The stone equals 14 pounds, or approximately 6.35029 kilograms, and is commonly used in the United Kingdom and Ireland for expressing human body weight. It has deep traditional roots, originating from stones used as counterweights in early commerce. Although largely replaced by metric units in most applications, the stone remains emotionally and culturally significant for personal weight expression in the UK. Many people find it more intuitive and relatable than kilograms due to long-standing social habits. The stone's endurance highlights how measurement systems reflect cultural identity as much as mathematical convenience. It is one of the few units still commonly used in conversation but not in scientific or industrial contexts.
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.