centigram

A centigram is a metric unit of mass equal to 0.01 grams, or 10 milligrams. Its symbol is cg. In the SI system, it occupies a middle ground between the gram (used for most laboratory and industrial measurements) and the milligram (used for pharmaceuticals and fine chemical work). While the gram itself is the base unit for practical mass measurement, the centigram appears in contexts where precision to the nearest 10 milligrams is both sufficient and conventional.

The centigram sees real use in pharmaceutical manufacturing, particularly in tablet and capsule production where individual doses may weigh between 100 milligrams and several grams. A 500 mg aspirin tablet is 5 cg. Food processing, confectionery manufacture, and spice blending also employ centigram-scale measurements. Laboratory balances capable of reading to 0.01 g (one centigram) are standard equipment in quality control departments, though digital scales have largely replaced mechanical ones that made the unit's subdivisions visually apparent.

The term itself follows the standard metric prefix convention: centi means one-hundredth, derived from Latin. It was formally adopted as part of the metric system in the late 18th century and remains official in SI. However, the unit has become somewhat orphaned in modern practice. Scientists and engineers increasingly express the same measurements in milligrams (more precise) or grams (simpler), leaving the centigram primarily to older standards, legacy equipment, and specific pharmaceutical contexts where it remains embedded in dose specifications and regulatory documentation.

Confusion occasionally arises from the centigram's proximity to other units. It is not a carat (used for gemstones and precious metals, equal to 200 milligrams), nor is it related to the avoirdupois or troy systems still used in some English-speaking trades. Metrication in industrial countries was largely complete by the 1970s, but older reference tables and balance calibrations sometimes list centigram markings, requiring workers to understand the unit even if they rarely use it for new measurements.