Definition: The gram is a unit of mass in the metric system equal to one thousandth of a kilogram (1g = 0.001 kg), the base unit of mass in the International System of Units (SI). It is also equal to 1,000 milligrams (mg), or 106 micrograms (μg) or 109 nanograms (ng) (SI units of mass), or approximately 0.00220462 pounds (lb) or 0.03527396 ounces (oz), which are US customary / Imperial units of mass.
The base unit of mass in the SI is the kilogram. However, within the name or symbol of an SI unit of mass the SI prefixes are used in combination with "gram" and not "kilogram" which already has a prefix (kilo-) included in its name. Examples of SI units of mass include: picogram (pg), nanogram (ng), microgram (μg), milligram (mg), centigram (cg), decigram (dg), etc. The kilogram is the only base unit of measurement in the International System of Units that has an SI prefix as part of its name.
The gram is commonly used worldwide as a unit of mass / weight in technical and scientific publications, in healthcare settings, and for solid ingredients in grocery shopping and cooking.
Symbol: g; also informal: gr, grm, grms, gm, gms
Also known as: gramme (plural: grammes, traditional British-English spelling)