Ounce (oz)
The ounce, symbol oz, is an imperial unit of mass derived from the Roman uncia, meaning “one-twelfth” of a pound. Standardized over centuries in England and later in the United States, one ounce is equivalent to 28.3495 grams. The ounce continues to be used for measuring food, postal items, and precious metals in regions employing imperial or US customary units. Its historical background and ongoing applications sustain its relevance alongside metric units.
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.