Convert Ounce (oz) to Dalton (Da) instantly.
About these units
Ounce (oz)
The ounce is a unit equal to 1/16 of a pound, or approximately 28.3495 grams, with roots in ancient Roman "uncia"—one-twelfth of a pound. The ounce is used for measuring small masses in cooking, postal services, gemstones (troy ounces), and various consumer goods. Despite not being part of the metric system, the ounce remains a staple in US everyday life, from food packaging to hardware components. Its small size gives it a practical niche where grams might feel too unfamiliar for some audiences. Multiple ounce variants exist historically—avoirdupois, troy, apothecary—but the avoirdupois ounce is now the standard in general commerce. Its endurance reflects the cultural weight of imperial units and the long history of Western measurement systems.
Dalton (Da)
The Dalton is numerically identical to 1 atomic mass unit and is commonly used in biochemistry and molecular biology, especially for expressing the masses of proteins, peptides, and macromolecules. While "u" is often preferred in physics and chemistry, the Dalton became the standard in biological sciences because it fits neatly into descriptions of amino acids, nucleotides, and biomolecular complexes. For example, a typical protein may have a mass of 50 kilodaltons (kDa). The adoption of the Dalton helped unify communication across genomics, proteomics, and structural biology. As molecular biology expands into nanotechnology and synthetic biology, the Dalton remains a central unit for describing the building blocks of life.