The word Ounce can be a unit of weight or a unit of liquid. It is very important to clearly define which unit when describing packaging. Many times I see just OZ (example 12 oz) and wonder do they mean FL. OZ. or NET WT. OZ. Depending on the unit of measure this could have two different meanings. Let’s have a closer look at the two different Ounces.

Fluid Ounce

When used with liquids to define volume or capacity the unit is Fluid Ounce and abbreviated FL. OZ. For example shampoo, lotions and motor oils are all measured in FL. OZ. A very common mistake is dropping the FL off the abbreviation and leaving it just OZ which could be mistaken to mean NET WT.OZ. When describing liquids the correct unit or measure is Fluid Ounces or FL. OZ.

Net Weight Ounce

When used to express mass or weight of products the unit is Net Weight Ounce and abbreviated NET WT. OZ. Also a very common mistake is to drop the NET WT. and only use OZ. (example 12 oz) which could be very confusing or misunderstood for the liquid measure. Some examples are mustard, powders and honey; all are measured by weight. When describing Mass or Weight of a product the correct unit of measure is Net Weight Ounce or NET WT. OZ.

As you can see Fluid Ounce and Net Weight Ounce are very different and are used for two different measurements. Make sure to use the proper Ounce and avoid any future possible misunderstandings.