The ounce (oz) is the name of several different units of mass, weight, or volume used in most British derived customary systems of measurement. The avoirdupois ounce equal to approximately 28.3 g.
- An ounce-force is 1/16 of a pound-force, or 0.2780139 newtons.
- A fluid ounce (abbreviated fl oz, fl. oz. or oz. fl.) is a unit of volume equal to about 28.4 ml in the imperial system or about 29.6 ml in the US system. The fluid ounce is sometimes referred to simply as an
ounce in applications where its use is implicit, such as bartending.
- Ounce derives from Latin uncia, a unit that was one-twelfth(1/12) of the Roman pound (libra).