:This article is about the unit of measure. Ounce is also another name for the snow leopard.The ounce is the name for a number of different units of mass (oz), and, confusingly, fluid volume (fl oz). See Imperial system of units and U.S. customary units for more about the frameworks within which these units are defined.
- avoirdupois ounce defined by the avoirdupois system of mass (see pound). There are 16 ounces in the avoirdupois pound. The avoirdupois ounce is approximately 28.3 grams.
- troy ounce defined by the troy system of mass. In troy weight, there are 12 ounces in a pound, and a troy pound is 5760 grains (about 373.24 g), rather than 7000 (about 453.59 g). Note: at roughly 31.1 g, the troy ounce is about 10 per cent more than the more-common avoirdupois ounce. These 31.1 g are now used only when weighing precious metals like gold and silver. One ounce of gold is always 31.1 g.
- apothecaries' ounce defined by the now-obsolete apothecaries' system of mass. This ounce was the same size as the troy ounce, and its symbol was ℥.
- The fluid ounce unit of volume also exists in the two versions of 28.4 ml (Imperial) and 29.6 ml (U.S.).
The Dutch term ons is a unit of mass that is considerably more, 100 g.
External links
Imperial units
US customary units
Units of mass
