Convert Grain (gr) to Exagram (Eg) instantly.
About these units
Grain (gr)
The grain, defined as exactly 64.79891 milligrams, is one of the oldest units of mass still in limited use today. Derived from the weight of average cereal grains such as barley or wheat, it became a universal tiny unit used across Europe for coins, medicine, and gunpowder. The grain persists in firearms and ammunition manufacturing because bullet weights are still listed in grains (e.g., a "150-grain bullet"). Reloaders and ballistic engineers rely on the grain as a fine unit suitable for measuring powder charges and projectile masses. It is also used in traditional gold and silver transactions, linking it to the troy system. The grain's longevity highlights how ancient agrarian measures can remain embedded in modern technological practices.
Exagram (Eg)
An exagram, equal to 10¹⁵ kilograms, is used to describe masses of planets, moons, and extremely large terrestrial reservoirs (e.g., total mass of Earth's atmosphere ≈ 5 Eg). Because of its enormous scale, the exagram rarely appears outside astrophysics or large-scale geophysics. When used, however, it provides a powerful sense of magnitude—allowing scientists to describe Earth systems at the grandest scales with simple, comprehensible numbers.