Convert Milligram to Grain

FromMilligram (mg)

ToGrain (gr)

Milligram

The milligram (mg) is a unit of mass in the metric system, equal to one-thousandth of a gram (0.001 g) or one-millionth of a kilogram (0.000001 kg). Since the gram and kilogram are defined using the Planck constant (h) in the International System of Units (SI), the milligram is indirectly tied to this same constant, ensuring precision and consistency.

Origin:

The milligram originated as a derived unit of mass within the metric system, introduced during the French Revolution in the late 18th century. As part of the decimal-based metric system, it was designed to provide a smaller and more convenient unit for measuring very light objects, especially in scientific and medical contexts. It is defined in relation to the gram, which was originally based on the mass of one cubic centimeter of pure water at 4°C.

Grain

The grain (gr) is a unit of mass used in both the imperial system and the U.S. customary system. It is defined as 1/7000 of a pound or approximately 64.79891 milligrams. The grain is one of the smallest units of mass commonly used and is primarily employed in measuring the weight of precious metals, gemstones, and ammunition (such as bullets).

Origin:

The grain traces its origins to ancient times and was originally based on the weight of a single grain of cereal, such as barley or wheat, which was used as a reference for small weight measurements. The term "grain" comes from the Latin "granum", meaning "grain" or "seed." The grain was used as a standard measure in ancient civilizations, including the Romans, and its use continued throughout medieval Europe. Over time, it was standardized in the 14th century as part of the Avoirdupois system and has remained in use for very precise measurements in modern times, especially in scientific fields, medicine, and the firearm industry.