What is a gram?

   Gram is the unit of weight in the metric system. It is the one-thousandth part of the international standard platinum-iridium prototype kilogram, and is the thousandth part of the weight of a liter of distilled water at 4 °C. In other words, it is the weight of a cubic centimeter of distilled water at this temperature. It is equal to 15.43248 grains. The subdivisions of the gram are expressed by Latin prefixes—decigram (1/10), centigram (1/100), milligram (1/1000); the multiples by Greek prefixes—decagram (10 grams), hectogram (100 grams), kilogram (1,000 grams). The kilogram is equal to about 2.2 Ibs.