What Is an Ounce (oz)?
Definition
Ounce (oz): A unit of mass used in the United States and the United Kingdom, symbol oz. The avoirdupois ounce is 1/16 of a pound, exactly 28.349523125 grams by definition.
The ounce (symbol oz) is a unit of mass used in the United States and the United Kingdom for food, mail and parcels. The everyday avoirdupois ounce is 1/16 of a pound, which makes it exactly 28.349523125 grams. The troy ounce used for gold and silver prices is a different, heavier unit.
Where it appears in the formulas
1 oz = 1/16 lb = 28.349523125 g. The weight converter uses this exact value (NIST Handbook 44, Appendix C). For example, 100 grams is about 3.5274 ounces, and 16 ounces make one pound.
Not the fluid ounce
The fluid ounce (fl oz) is a unit of volume. The weight converter converts only the ounce of mass.