Convert Stone (st) to Ton (Assay) (UK) (AT (UK)) 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.
Ton (Assay) (UK) (AT (UK))
The UK assay ton, slightly different from the US version, is defined as 32.666 grams. Like its American counterpart, it was designed so that milligram-level assay results could be easily interpreted as ounces of metal per ton of ore. In British mining operations of the 19th and early 20th centuries, the UK assay ton streamlined economic decision-making by directly correlating lab-scale measurements with bulk extraction expectations. Although now historical, its existence illustrates how different countries tailored their measurement systems to local mining economics and metal markets.