Abbreviations

• Selected abbreviations are listed below.

• Other common abbreviations used in the medical field:

• 1 fluid ounce = 30 milliliters

• One liter of pure water weighs approximately one kilogram so 1cc (mL) of water weighs 1 gram.

• "A spoonful" generally means heaped or rounded, with as much above the bowl of the spoon as in the spoon. However, a measure of liquid is a level spoonful.

• 1 teaspoonful = 5 milliliters

• 1 tablespoonful = 15 milliliters

• 1 ounce = 30 grams

• 1 gram = 15 grains

• In 1866, the United Stated Congress legalized the use of the metric system within the United States. The law also established approximate equivalents between customary and metric measurements.

• 1 gram = 1,000 milligrams

• 1 milligram = 1,000 micrograms

Exact Equivalents

• Note: Exact equivalents are used for compounding and calculations requiring a high degree of accuracy.

• International units: An old measurement of vitamin activity determined by biological methods as opposed to new measures that are determined by direct chemical analysis.

• An international unit is quantity of a biologic (such as a vitamin) that produces a particular biological effect agreed upon as an international standard. Many health foods and supplements still use i.u. (IU).

• A grain is a unit of weight in the U.S. Customary System.

• The apothecaries' system of mass is an obsolete system formerly used by apothecaries (now called pharmacists or chemists) in English-speaking countries. Sometimes "ap" is added to the front of the unit to identify it as part of the apothecaries' system.

• During the first half of the 20th Century, the apothecaries' system was replaced by the metric system.