Kilogram (kg)
The kilogram, symbolized as kg, is the SI base unit of mass, equivalent to 1,000 grams. Introduced in France in 1795, it was historically defined by a platinum-iridium physical prototype stored near Paris. In 2019, the kilogram was redefined by reference to the Planck constant for a universal and precise definition based on physics rather than an object. The kilogram is fundamental in science, industry, and daily life, providing a standardized unit of measurement for a broad range of applications. Its adoption ensures seamless consistency worldwide.
Stone (st)
The stone (st) is a traditional British unit of mass, standardized as 14 pounds, which is roughly 6.35 kilograms. Its history dates back to medieval England, when stones of different weights were used as standards in trading. While most countries now use kilograms for official measurements, the stone is still frequently used in the UK and Ireland, especially to state a person’s body weight. Its ongoing use highlights both cultural tradition and the continued relevance of non-metric measures in everyday life.